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236 results on '"Laboratoire de Chimie des Processus Biologiques (LCPB)"'

1. Flavin-Dependent Methylation of RNAs: Complex Chemistry for a Simple Modification

Author: Henri Grosjean, Marc Fontecave, Djemel Hamdane, Laboratoire de Chimie des Processus Biologiques ( LCPB ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Collège de France ( CdF ) -Centre National de la Recherche Scientifique ( CNRS ), Structure et dynamique des ARN ( RNAStr ), Département Biologie des Génomes ( DBG ), Institut de Biologie Intégrative de la Cellule ( I2BC ), Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Sud - Paris 11 ( UP11 ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Sud - Paris 11 ( UP11 ) -Institut de Biologie Intégrative de la Cellule ( I2BC ), Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Sud - Paris 11 ( UP11 ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Sud - Paris 11 ( UP11 ), Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Sud - Paris 11 ( UP11 ), Chaire Chimie des processus biologiques, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Structure et dynamique des ARN (RNAStr), Département Biologie des Génomes (DBG), Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Collège de France - Chaire Chimie des processus biologiques
Subjects: 0301 basic medicine, S-Adenosylmethionine, Methyltransferase, Stereochemistry, RNA methylation, [SDV]Life Sciences [q-bio], Flavin group, methylation mechanism, Methylation, Cofactor, 03 medical and health sciences, chemistry.chemical_compound, Structural Biology, flavoenzyme, Molecular Biology, Tetrahydrofolates, Flavin adenine dinucleotide, tRNA Methyltransferases, [ SDV ] Life Sciences [q-bio], 030102 biochemistry & molecular biology, biology, 5-methyluridine, RNA, Iminium, 030104 developmental biology, chemistry, Flavin-Adenine Dinucleotide, biology.protein, methyltransferase
Abstract: International audience; RNA methylation is the most abundant and evolutionarily conserved chemical modification of bases or ribose in noncoding and coding RNAs. This rather simple modification has nevertheless major consequences on the function of maturated RNA molecules and ultimately on their cellular fates. The methyl group employed in the methylation is almost universally derived from S-adenosyl-L-methionine via a simple SN2 displacement reaction. However, in some rare cases, the carbon originates from N5,N10-methylenetetrahydrofolate (CH2=THF). Here, a methylene group is transferred first and requires a subsequent reduction step (2e-+H+) via the flavin adenine dinucleotide hydroquinone (FADH-) to form the final methylated derivative. This FAD/folate-dependent mode of chemical reaction, called reductive methylation, is thus far more complex than the usual simple S-adenosyl-L-methionine-dependent one. This reaction is catalyzed by flavoenzymes, now named TrmFO and RlmFO, which respectively modify transfer and ribosomal RNAs. In this review, we briefly recount how these new RNA methyltransferases were discovered and describe a novel aspect of the chemistry of flavins, wherein this versatile biological cofactor is not just a simple redox catalyst but is also a new methyl transfer agent acting via a critical CH2=(N5)FAD iminium intermediate. The enigmatic structural reorganization of these enzymes that needs to take place during catalysis in order to build their active center is also discussed. Finally, recent findings demonstrated that this flavin-dependent mechanism is also employed by enzymatic systems involved in DNA synthesis, suggesting that the use of this cofactor as a methylating agent of biomolecules could be far more usual than initially anticipated.
Published: 2016
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2. Reactivity of the Excited States of the H-Cluster of FeFe Hydrogenases

Author: Carole Baffert, Claudio Greco, Luca Bertini, Souvik Roy, Charles Gauquelin, Isabelle Meynial-Salles, Matteo Sensi, Vincent Artero, Hervé Bottin, Luca De Gioia, Marc Fontecave, Laure Saujet, Christophe Léger, Philippe Soucaille, Vincent Fourmond, Giorgio Caserta, Bioénergétique et Ingénierie des Protéines (BIP ), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Department of Biotechnologies and Biosciences, University of Milano-Bicocca, Department of Earth and Environmental Sciences [Milano], Università degli Studi di Milano-Bicocca [Milano] (UNIMIB), Laboratoire de Chimie des Processus Biologiques (LCPB), Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF)-Université Pierre et Marie Curie - Paris 6 (UPMC), Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés (LISBP), Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de la Recherche Agronomique (INRA), Institut de Biologie Intégrative de la Cellule (I2BC), Université Paris-Sud - Paris 11 (UP11)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Institut de Biologie et de Technologies de Saclay (IBITECS), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Bioénergétique et Ingénierie des Protéines ( BIP ), Aix Marseille Université ( AMU ) -Centre National de la Recherche Scientifique ( CNRS ), Department of Earth and Environmental Sciences, Università degli Studi di Milano-Bicocca [Milano], Laboratoire de Chimie des Processus Biologiques ( LCPB ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Collège de France ( CdF ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés ( LISBP ), Institut National de la Recherche Agronomique ( INRA ) -Institut National des Sciences Appliquées - Toulouse ( INSA Toulouse ), Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Centre National de la Recherche Scientifique ( CNRS ), Institut de Biologie Intégrative de la Cellule ( I2BC ), Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ), Institut de Biologie et de Technologies de Saclay ( IBITECS ), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ), Laboratoire de Chimie et Biologie des Métaux ( LCBM - UMR 5249 ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ), Università degli Studi di Milano-Bicocca = University of Milano-Bicocca (UNIMIB), Collège de France - Chaire Chimie des processus biologiques, Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique (INRA)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), CNRS, Aix Marseille Universite, INSA, CEA, ANR-12-BS08-0014,ECCHYMOSE,Etudes d'hydrogénases à Fer par électrochimie: mécanisme et optimisation pour la photoproduction d'hydrogène(2012), ANR-14-CE05-0010,HEROS,Hydrogénases résistantes à l'Oxygène(2014), ANR-11-LABX-0003,ARCANE,Grenoble, une chimie bio-motivée(2011), ANR-11-IDEX-0001,Amidex,INITIATIVE D'EXCELLENCE AIX MARSEILLE UNIVERSITE(2011), Chaire Chimie des processus biologiques, Université Pierre et Marie Curie - Paris 6 (UPMC)-Collège de France (CdF)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Sensi, M, Baffert, C, Greco, C, Caserta, G, Gauquelin, C, Saujet, L, Fontecave, M, Roy, S, Artero, V, Soucaille, P, Meynial Salles, I, Bottin, H, DE GIOIA, L, Fourmond, V, Léger, C, and Bertini, L
Subjects: Hydrogenase, 010402 general chemistry, Photochemistry, 01 natural sciences, Biochemistry, [ CHIM ] Chemical Sciences, Catalysis, [ CHIM.CATA ] Chemical Sciences/Catalysis, Colloid and Surface Chemistry, Cluster (physics), [CHIM]Chemical Sciences, Reactivity (chemistry), Hydrogen, hydrogenase, biology, 010405 organic chemistry, Chemistry, Active site, General Chemistry, Time-dependent density functional theory, [CHIM.CATA]Chemical Sciences/Catalysis, 0104 chemical sciences, [ PHYS.PHYS.PHYS-CHEM-PH ] Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Covalent bond, Excited state, biology.protein
Abstract: International audience; FeFe hydrogenases catalyze H-2 oxidation and formation at an inorganic active site (the "H-cluster"), which consists of a [Fe-2(CO)(3)(CN)(2)(dithiomethylamine)] subcluster covalently attached to a Fe4S4 subcluster. This active site is photosensitive: visible light has been shown to induce the release of exogenous CO (a reversible inhibitor of the enzyme), shuffle the intrinsic CO ligands, and even destroy the H-cluster. These reactions must be understood because they may negatively impact the Use of hydrogenase for the photoproduction of H-2. Here, we explore in great detail the reactivity of the excited states of the H-duster under catalytic conditions by examining, both experimentally and using TDDFT calculations, the simplest photochemical reaction: the binding and release of exogenous CO. A simple dyad model can be used to predict which excitations are active. This could be used for probing other, aspects of the photoreactivity of the H-cluster.
Published: 2016
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3. Destabilizing an interacting motif strengthens the association of a designed ankyrin repeat protein with tubulin

Author: Ludovic Pecqueur, Magali Aumont-Nicaise, Andreas Plückthun, Shoeb Ahmad, Marcel Knossow, Birgit Dreier, Djemel Hamdane, Benoît Gigant, Biochimie Structurale des Microtubules, des Kinésines et de leurs Cargos ( MIKICA ), Département Biochimie, Biophysique et Biologie Structurale ( B3S ), Institut de Biologie Intégrative de la Cellule ( I2BC ), Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Institut de Biologie Intégrative de la Cellule ( I2BC ), Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ), Department of Biochemistry [Zurich], University of Zürich [Zürich] ( UZH ), Laboratoire de Chimie des Processus Biologiques ( LCPB ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Collège de France ( CdF ) -Centre National de la Recherche Scientifique ( CNRS ), Mesures d'interactions protéine-protéine ( PIM ), Département Plateforme ( PF I2BC ), ANR-10-INSB-05-01,FRISBI,French Infrastructure for Integrated Structural Biology, ANR-12-BSV8-0002-01,(Kines-Tubul-DARP)-in, University of Zurich, Knossow, Marcel, Biochimie Structurale des Microtubules, des Kinésines et de leurs Cargos (MIKICA), Département Biochimie, Biophysique et Biologie Structurale (B3S), Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Universität Zürich [Zürich] = University of Zurich (UZH), Laboratoire de Chimie des Processus Biologiques (LCPB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Mesures d'interactions protéine-protéine (PIM), Département Plateforme (PF I2BC), ANR-10-INBS-0005,FRISBI,Infrastructure Française pour la Biologie Structurale Intégrée(2010), and ANR-12-BSV8-0002,(Kines-Tubul-DARP)-in,Le cycle structural des kinésines: l'interaction kinésine-tubuline à résolution atomique en relation avec l'état nucléotidique.(2012)
Subjects: Ankyrins, Models, Molecular, 0301 basic medicine, Conformational change, [SDV]Life Sciences [q-bio], Amino Acid Motifs, Enzyme-Linked Immunosorbent Assay, 610 Medicine & health, Plasma protein binding, Protein Engineering, Article, Tubulin binding, Affinity maturation, 03 medical and health sciences, Tubulin, Escherichia coli, 10019 Department of Biochemistry, Cloning, Molecular, Genetics, 1000 Multidisciplinary, Multidisciplinary, [ SDV ] Life Sciences [q-bio], 030102 biochemistry & molecular biology, biology, Circular Dichroism, Escherichia coli Proteins, Protein engineering, Surface Plasmon Resonance, Ankyrin Repeat, Kinetics, Spectrometry, Fluorescence, 030104 developmental biology, DARPin, Mutagenesis, Mutation, Biophysics, biology.protein, 570 Life sciences, Ankyrin repeat, Ribosomes, Protein Binding
Abstract: Affinity maturation by random mutagenesis and selection is an established technique to make binding molecules more suitable for applications in biomedical research, diagnostics and therapy. Here we identified an unexpected novel mechanism of affinity increase upon in vitro evolution of a tubulin-specific designed ankyrin repeat protein (DARPin). Structural analysis indicated that in the progenitor DARPin the C-terminal capping repeat (C-cap) undergoes a 25° rotation to avoid a clash with tubulin upon binding. Additionally, the C-cap appears to be involved in electrostatic repulsion with tubulin. Biochemical and structural characterizations demonstrated that the evolved mutants achieved a gain in affinity through destabilization of the C-cap, which relieves the need of a DARPin conformational change upon tubulin binding and removes unfavorable interactions in the complex. Therefore, this specific case of an order-to-disorder transition led to a 100-fold tighter complex with a subnanomolar equilibrium dissociation constant, remarkably associated with a 30% decrease of the binding surface.
Published: 2016
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4. Mentesh Tepe, an early settlement of the Shomu-Shulaveri Culture in Azerbaijan

Author: Laurence Bouquet, Modwene Poulmarc'H, Bertille Lyonnet, Elsa Jovenet, Antoine Courcier, Farhad Guliyev, Denis Guilbeau, Norbert Benecke, Emmanuel Baudouin, Michel Fontugne, Caroline Hamon, Laure Pecqueur, Gaëlle Bruley-Chabot, Anaïck Samzun, Pascal Raymond, Emeline Degorre, Gaëlle Le Dosseur, Laurence Astruc, Travaux et recherches archéologiques sur les cultures, les espaces et les sociétés (TRACES), Ministère de la Culture et de la Communication (MCC)-École des hautes études en sciences sociales (EHESS)-Université Toulouse - Jean Jaurès (UT2J)-Centre National de la Recherche Scientifique (CNRS), Archéologies et Sciences de l'Antiquité (ArScAn), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris Nanterre (UPN)-Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS), Du village à l’État au Proche et Moyen-Orient (Vepmo), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris Nanterre (UPN)-Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS)-Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris Nanterre (UPN)-Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS), Préhistoire et Technologie (PréTech), Centre National de la Recherche Scientifique (CNRS)-Université Paris Nanterre (UPN), Proche-Orient, Caucase, Iran : Diversités et Continuités (PROCLAC), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Collège de France (CdF (institution))-Centre National de la Recherche Scientifique (CNRS), Baku State University, Baku AZ1141, 23 Z. Khalilov St, Baku, Azerbaijan, Institut national de recherches archéologiques préventives (Inrap), Dauphine Recherches en Management (DRM), Université Paris Dauphine-PSL, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Géochrononologie Traceurs Archéométrie (GEOTRAC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), EVEHA (Etudes et valorisations archeologiques), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris 8 Vincennes-Saint-Denis (UP8)-Université Paris Nanterre (UPN)-Ministère de la Culture et de la Communication (MCC)-Institut national de recherches archéologiques préventives (Inrap)-Centre National de la Recherche Scientifique (CNRS), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris 8 Vincennes-Saint-Denis (UP8)-Université Paris Nanterre (UPN)-Ministère de la Culture et de la Communication (MCC)-Institut national de recherches archéologiques préventives (Inrap)-Centre National de la Recherche Scientifique (CNRS)-Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris 8 Vincennes-Saint-Denis (UP8)-Université Paris Nanterre (UPN)-Ministère de la Culture et de la Communication (MCC)-Institut national de recherches archéologiques préventives (Inrap)-Centre National de la Recherche Scientifique (CNRS), Université Paris Nanterre (UPN)-Centre National de la Recherche Scientifique (CNRS), Chercheur indépendant, Department of Natural Sciences, German Archaeological Institute (DAI), Trajectoires - UMR 8215, Université Paris 1 Panthéon-Sorbonne (UP1)-Centre National de la Recherche Scientifique (CNRS), ARCHEORIENT - Environnements et sociétés de l'Orient ancien (Archéorient), Université Lumière - Lyon 2 (UL2)-Centre National de la Recherche Scientifique (CNRS), Deutsches Bergbau-Museum Bochum (DBM), DBM, ANR-09-FRAL-0002,Ancient Kura,Cultures anciennes du Sud Caucase: paléo-environnement, mode de vie et exploitation des ressources dans la Moyenne Vallée de la Kura, du 6e au 3e millénaire(2009), ANR-12-FRAL-0011,Kura in Motion!,'Kura in Motion!' Hommes, plantes et animaux dans leur dynamique au sein de la moyenne vallée de la Kura, 6e-3e millénaires BCE.(2012), École Pratique des Hautes Études (EPHE), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris 8 Vincennes-Saint-Denis (UP8)-Université Paris Nanterre (UPN)-Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris 8 Vincennes-Saint-Denis (UP8)-Université Paris Nanterre (UPN)-Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS)-Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris 8 Vincennes-Saint-Denis (UP8)-Université Paris Nanterre (UPN)-Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS), École pratique des hautes études (EPHE)-Collège de France (CdF)-Institut National des Langues et Civilisations Orientales (Inalco)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie des Processus Biologiques (LCPB), Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF)-Université Pierre et Marie Curie - Paris 6 (UPMC), Laboratoire de Physiologie Cellulaire et Moléculaire des Plantes (UR5), Université Pierre et Marie Curie - Paris 6 (UPMC), Département Génie Biologique / IUT de Saint-Brieuc, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Centre National de la Recherche Scientifique (CNRS)-Ministère de la Culture et de la Communication (MCC)-Université Paris Nanterre (UPN)-Université Panthéon-Sorbonne (UP1), The German Archaeological Institute, Université Panthéon-Sorbonne (UP1)-Centre National de la Recherche Scientifique (CNRS), Proche-Orient, Caucase, Iran : Diversités et Continuités ( PROCLAC ), École pratique des hautes études ( EPHE ) -Collège de France ( CdF ) -Institut National des Langues et Civilisations Orientales ( Inalco ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Chimie des Processus Biologiques ( LCPB ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Collège de France ( CdF ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Physiologie Cellulaire et Moléculaire des Plantes ( UR5 ), Université Pierre et Marie Curie - Paris 6 ( UPMC ), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] ( LSCE ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ), Université de Rennes 1 ( UR1 ), Université de Rennes ( UNIV-RENNES ) -Université de Rennes ( UNIV-RENNES ), Archéologies et Sciences de l'Antiquité ( ArScAn ), Université Panthéon-Sorbonne ( UP1 ) -Université Paris Nanterre ( UPN ) -Ministère de la Culture et de la Communication ( MCC ) -Centre National de la Recherche Scientifique ( CNRS ), Préhistoire et Technologie ( PréTech ), Université Paris Nanterre ( UPN ) -Centre National de la Recherche Scientifique ( CNRS ), Université Panthéon-Sorbonne ( UP1 ) -Centre National de la Recherche Scientifique ( CNRS ), ARCHEORIENT - Environnements et sociétés de l'Orient ancien ( Archéorient ), Université Lumière - Lyon 2 ( UL2 ) -Centre National de la Recherche Scientifique ( CNRS ), Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), and École des hautes études en sciences sociales (EHESS)-Université Toulouse - Jean Jaurès (UT2J)-Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [ SDU.OCEAN ] Sciences of the Universe [physics]/Ocean, Atmosphere, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, 010506 paleontology, 010504 meteorology & atmospheric sciences, [SHS.ARCHEO]Humanities and Social Sciences/Archaeology and Prehistory, [SHS.ANTHRO-BIO]Humanities and Social Sciences/Biological anthropology, Chalcolithic, 01 natural sciences, Archaeology, Shomu-Shulaveri Culture, [SHS]Humanities and Social Sciences, Geography, Bronze Age, Stage (stratigraphy), Inhumation, [ SDU.ENVI ] Sciences of the Universe [physics]/Continental interfaces, environment, Caspian Sea level mobility, Climate change, Neolithic, Settlement (litigation), Domestication, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Earth-Surface Processes
Abstract: International audience; Excavations at Mentesh Tepe, western Azerbaijan, have unearthed Neolithic levels dated to an early stage of the Shomu-Shulaveri Culture, with a specific material culture and several inhumations among which a multiple burial. At that stage, already a full domestication of plants and animals is evident. Many questions have been raised concerning the origins of this culture, and its end is also still obscure. Relations with societies in the north-Mesopotamian area have again recently been evidenced at its beginnings. Mentesh Tepe, with its exceptional succession of occupations from the Neolithic to the Early Bronze Age, could help providing some clues for the links between the Neolithic and the Chalcolithic periods. The site is presented here under different points of views (architecture, burials, material culture) but in a preliminary stage since many studies are still in progress. Questions are raised about the climate and the apparent absence of pre-and post-Shomu-Shulaveri Culture possibly due to silting or erosion processes linked with the mobility of the Caspian Sea level.
Published: 2016
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5. A miniature airlock system to aid the cryo-cooling of protein crystals grown under anoxic conditions

Author: Peter van der Linden, Sylvain Engilberge, Mohamed Atta, Philippe Carpentier, Partnership for Soft Condensed Matter, European Synchrotron Radiation Facility, European Synchroton Radiation Facility [Grenoble] (ESRF), Biocatalyse (BIOCAT), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017)
Subjects: oxygen-employing enzymes, gloveboxes, oxygen-sensitive proteins, protein crystallography, [CHIM.CRIS]Chemical Sciences/Cristallography, anoxia, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, flash-cooling, General Biochemistry, Genetics and Molecular Biology
Abstract: Crystallographic studies of structures and mechanisms of dioxygen-employing enzymes or oxygen-sensitive proteins usually require these molecules to be prepared and crystallized under anoxic conditions in gloveboxes. Handling, cryo-cooling and extraction of these crystals from gloveboxes for X-ray data collection can be a tricky operation, during which samples might be ruined if they are accidentally exposed to atmospheric oxygen. This work reports the design of a new miniature airlock system and describes the associated method in order to simplify these tasks. The system allows flash-cooling of crystals harvested in a glovebox directly into an external liquid nitrogen container via a miniature airlock while maintaining strict anoxic conditions. The method was assessed using hen egg-white lysozyme crystals soaked in dihydroresorufin (an O2 indicator) and with the reduced tRNA-hydroxylase enzyme MiaE.
Published: 2022
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6. Light-Driven Hydrogen Evolution Reaction Catalyzed by a Molybdenum-Copper Artificial Hydrogenase

Author: Labidi, Raphaël, Faivre, Bruno, Carpentier, Philippe, Veronesi, Giulia, Solé- Daura, Albert, Bjornsson, Ragnar, Léger, Christophe, Gotico, Philipp, Li, Yun, Atta, Mohamed, Fontecave, Marc, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Biocatalyse (BIOCAT), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Chimie computationnelle, modélisation et rayons X (COMX), Laboratoire de Bioénergétique et Ingénierie des Protéines (CNRS, Aix Marseille Université, Marseille 13009), Laboratoire des Mécanismes fondamentaux de la Bioénergétique (LMB), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Grants 'LABEX DYNAMO', ANR-11-LABX-0011
Subjects: artificial enzyme, molybdenum-copper clusters, hydrogenase artificial enzyme orange protein molybdenum-copper clusters, [CHIM]Chemical Sciences, hydrogenase, orange protein
Abstract: International audience; Orange Protein (Orp) is a small bacterial metalloprotein of unknown function that harbors a unique molybdenum/copper (Mo/Cu) heterometallic cluster, [S2MoS2CuS2MoS2]3−. In this paper, the performance of Orp as a catalyst for the photocatalytic reduction of protons into H2 has been investigated under visible light irradiation. We report the complete biochemical and spectroscopic characterization of holo-Orp containing the [S2MoS2CuS2MoS2]3− cluster, with docking and molecular dynamics simulations suggesting a positively charged Arg, Lys-containing pocket as the binding site. Holo-Orp exhibits an excellent photocatalytic activity, in the presence of ascorbate as the sacrificial electron donor and [Ru(bpy)3]Cl2 as the photosensitizer, for hydrogen evolution with a maximum turnover number of 890 after 4 hours irradiation. DFT calculations were used to propose a consistent reaction mechanism in which the terminal sulfur atoms are playing a key role in promoting H2 formation. A series of dinuclear [S2MS2M’S2MS2](4n)− clusters, with M = MoVI, WVI and M’(n+) = CuI, FeI, NiI, CoI , ZnII, CdII were assembled in Orp, leading to different M/M’-Orp versions which are shown to display catalytic activity, with the Mo/Fe-Orp catalyst giving a remarkable TON of 1150 after 2.5 hours reaction and an initial turnover frequency (TOF°) of 800 h-1 establishing a record among previously reported artificial hydrogenases.
Published: 2023
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7. Dihydrouridine in the Transcriptome: New Life for This Ancient RNA Chemical Modification

Author: Damien Brégeon, Ludovic Pecqueur, Sabrine Toubdji, Claudia Sudol, Murielle Lombard, Marc Fontecave, Valérie de Crécy-Lagard, Yuri Motorin, Mark Helm, Djemel Hamdane, hamdane, djemel, Institut de Biologie Paris Seine (IBPS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Collège de France - Chaire Chimie des processus biologiques, Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), University of Florida [Gainesville] (UF), Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Ingénierie, Biologie et Santé en Lorraine (IBSLor), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), and Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU)
Subjects: [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], RNA, Transfer, [SDV.BBM.BS] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], Protein Biosynthesis, RNA, Molecular Medicine, RNA, Messenger, General Medicine, RNA Processing, Post-Transcriptional, Transcriptome, Biochemistry
Abstract: International audience; Until recently, post-transcriptional modifications of RNA were largely restricted to noncoding RNA species. However, this belief seems to have quickly dissipated with the growing number of new modifications found in mRNA that were originally thought to be primarily tRNA-specific, such as dihydrouridine. Recently, transcriptomic profiling, metabolic labeling, and proteomics have identified unexpected dihydrouridylation of mRNAs, greatly expanding the catalog of novel mRNA modifications. These data also implicated dihydrouridylation in meiotic chromosome segregation, protein translation rates, and cell proliferation. Dihydrouridylation of tRNAs and mRNAs are introduced by flavin-dependent dihydrouridine synthases. In this review, we will briefly outline the current knowledge on the distribution of dihydrouridines in the transcriptome, their chemical labeling, and highlight structural and mechanistic aspects regarding the dihydrouridine synthases enzyme family. A special emphasis on important research directions to be addressed will also be discussed. This new entry of dihydrouridine into mRNA modifications has definitely added a new layer of information that controls protein synthesis.
Published: 2022
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8. Identification of 2-Methylthio-methylenethio-N-6-(cis-4-hydroxyisopentenyl)adenosine (msms(2)io(6)A(37)) as a Novel Modification at Adenosine 37 of tRNAs from Salmonella typhimurium

Author: Libiad, Marouane, Douki, Thierry, Fontecave, Marc, Atta, Mohamed, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Chimie Interface Biologie pour l’Environnement, la Santé et la Toxicologie (CIBEST ), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Collège de France - Chaire Chimie des processus biologiques, Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Biocatalyse (BIOCAT), and Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249)
Subjects: tRNA modifications, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, tRNA-diiron monooxygenase, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, hydroxylation, LC-MS
Abstract: International audience; Post-transcriptional modifications of tRNA nucleotide are important determinants in folding, structure and function. We have successfully identified and characterized a new modified base named 2-methylthio-methylenethio-N-6-(cis-4-hydroxyisopentenyl)adenosine, which is present at position 37 in some tRNAs. We also showed that this new modified adenosine is derived from the known 2-methylthio-methylenethio-N-6-(isopentenyl)adenosine nucleoside by a catalytic cycle of the tRNA-diiron monooxygenase, MiaE, present in Salmonella typhimurium.
Published: 2023
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9. Carbon Dioxide Reduction: A Bioinspired Catalysis Approach

Author: Yun Li, Thibault Fogeron, Maria Gómez-Mingot, Marc Fontecave, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Chaire Chimie des processus biologiques, and Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010405 organic chemistry, Chemistry, Ligand, Molybdopterin, Context (language use), General Medicine, General Chemistry, Carbon Dioxide, 010402 general chemistry, Formate Dehydrogenases, 01 natural sciences, Combinatorial chemistry, Catalysis, 0104 chemical sciences, chemistry.chemical_compound, 13. Climate action, Pyran, Catalytic Domain, [CHIM]Chemical Sciences, Chelation, Sulfur, Organometallic chemistry, Electrochemical reduction of carbon dioxide
Abstract: ConspectusWhile developed in a number of directions, bioinspired catalysis has been explored only very recently for CO2 reduction, a challenging reaction of prime importance in the context of the energetic transition to be built up. This approach is particularly relevant because nature teaches us that CO2 reduction is possible, with low overpotentials, high rates, and large selectivity, and gives us unique clues to design and discover new interesting molecular catalysts. Indeed, on the basis of our relatively advanced understanding of the structures and mechanisms of the active sites of fascinating metalloenzymes such as formate dehydrogenases (FDHs) and CO dehydrogenases (CODHs), it is possible to design original, active, selective, and stable molecular catalysts using the bioinspired approach. These metalloenzymes use fascinating metal centers: in FDHs, a Mo(W) mononuclear ion is coordinated by four sulfur atoms provided by a specific organic ligand, molybdopterin (MPT), containing a pyranopterin heterocycle (composed of a pyran ring fused with a pterin unit) and two sulfhydryl groups for metal chelation; in CODHs, catalytic activity depends on either a unique nickel-iron-sulfur cluster or a dinuclear Mo-Cu complex in which the Mo ion is chelated by an MPT ligand. As a consequence, the novel class of catalysts, designed by bioinspiration, consists of mononuclear Mo, W, and Ni and as well as dinuclear Mo-Cu and Ni-Fe complexes in which the metal ions are coordinated by sulfur ligands, more specifically, dithiolene chelates mimicking the natural MPT cofactor. In general, their activity is evaluated in electrochemical systems (cyclic voltammetry and bulk electrolysis) or in photochemical systems (in the presence of a photosensitizer and a sacrificial electron donor) in solution. This research is multidisciplinary because it implies detailed biochemical, functional, and structural characterization of the inspiring enzymes together with synthetic organic and organometallic chemistry and molecular catalysis studies. The most important achievements in this direction, starting from the first report of a catalytically active biomimetic bis-dithiolene-Mo complex in 2015, are discussed in this Account, highlighting the challenging issues associated with synthesis of such sophisticated ligands and molecular catalysts as well as the complexity of reaction mechanisms. While the very first active biomimetic catalysts require further improvement, in terms of performance, they set the stage in which molecular chemistry and enzymology can synergistically cooperate for a better understanding of why nature has selected these sites and for developing highly active catalysts.
Published: 2021
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10. A subclass of archaeal U8-tRNA sulfurases requires a [4Fe-4S] cluster for catalysis

Author: Nisha He, Jingjing Zhou, Ornella Bimai, Jonathan Oltmanns, Jean-Luc Ravanat, Christophe Velours, Volker Schünemann, Marc Fontecave, Béatrice Golinelli-Pimpaneau, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Technische Universität Kaiserslautern (TU Kaiserslautern), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Microbiologie Fondamentale et Pathogénicité (MFP), Université Bordeaux Segalen - Bordeaux 2-Centre National de la Recherche Scientifique (CNRS), Collège de France - Chaire Chimie des processus biologiques, and Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], Genetics, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM]
Abstract: Sulfuration of uridine 8, in bacterial and archaeal tRNAs, is catalyzed by enzymes formerly known as ThiI, but renamed here TtuI. Two different classes of TtuI proteins, which possess a PP-loop-containing pyrophosphatase domain that includes a conserved cysteine important for catalysis, have been identified. The first class, as exemplified by the prototypic Escherichia coli enzyme, possesses an additional C-terminal rhodanese domain harboring a second cysteine, which serves to form a catalytic persulfide. Among the second class of TtuI proteins that do not possess the rhodanese domain, some archaeal proteins display a conserved CXXC + C motif. We report here spectroscopic and enzymatic studies showing that TtuI from Methanococcus maripaludis and Pyrococcus furiosus can assemble a [4Fe–4S] cluster that is essential for tRNA sulfuration activity. Moreover, structural modeling studies, together with previously reported mutagenesis experiments of M. maripaludis TtuI, indicate that the [4Fe–4S] cluster is coordinated by the three cysteines of the CXXC + C motif. Altogether, our results raise a novel mechanism for U8-tRNA sulfuration, in which the cluster is proposed to catalyze the transfer of sulfur atoms to the activated tRNA substrate.
Published: 2022
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11. Highly Selective Copper-Based Catalysts for Electrochemical Conversion of Carbon Monoxide to Ethylene Using a Gas-Fed Flow Electrolyzer

Author: Hong Phong Duong, Ngoc-Huan Tran, Gwenaëlle Rousse, Sandrine Zanna, Moritz W. Schreiber, Marc Fontecave, Collège de France - Chaire Chimie des processus biologiques, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Collège de France - Chaire Chimie du solide et énergie, Chimie du solide et de l'énergie (CSE), Réseau sur le stockage électrochimique de l'énergie (RS2E), Aix Marseille Université (AMU)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Collège de France (CdF (institution))-Université de Picardie Jules Verne (UPJV)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Pau et des Pays de l'Adour (UPPA)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Université Grenoble Alpes (UGA)-Nantes Université (Nantes Univ)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Université de Montpellier (UM), and Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: General Chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, Catalysis
Published: 2022
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12. Heterogenised Molecular Catalysts for Sustainable Electrochemical CO 2 Reduction

Author: Domenico Grammatico, Andrew J. Bagnall, Ludovico Riccardi, Marc Fontecave, Bao‐Lian Su, Laurent Billon, Uppsala University, Eindhoven University of Technology [Eindhoven] (TU/e), Collège de France - Chaire Chimie des processus biologiques, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), AIT Austrian Institute of Technology GmbH, Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux (IPREM), Université de Pau et des Pays de l'Adour (UPPA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and European Project: 765376,eSCALED
Subjects: [CHIM.POLY]Chemical Sciences/Polymers, Solar Fuels, Heterogenization, Electrochemical Reduction, [CHIM]Chemical Sciences, Molecular Catalysts, [CHIM.MATE]Chemical Sciences/Material chemistry, General Medicine, General Chemistry, Catalysis, Carbon Dioxide Reduction
Abstract: International audience; There has been a rapid rise in interest regarding the advantages of support materials to protect and immobilise molecular catalysts for the carbon dioxide reduction reaction (CO2RR) in order to overcome the weaknesses of many well-known catalysts in terms of their stability and selectivity. In this Review, the state of the art of different catalyst-support systems for the CO2RR is discussed with the intention of leading towards standard benchmarking for comparison of such systems across the most relevant supports and immobilisation strategies, taking into account these multiple pertinent metrics, and also enabling clearer consideration of the necessary steps for further progress. The most promising support systems are described, along with a final note on the need for developing more advanced experimental and computational techniques to aid the rational design principles that are prerequisite to prospective industrial upscaling.
Published: 2022
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13. Molecular Inhibition for Selective CO 2 Conversion

Author: Charles E. Creissen, José Guillermo Rivera de la Cruz, Dilan Karapinar, Dario Taverna, Moritz W. Schreiber, Marc Fontecave, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Total Research and Technology Feluy ( [TRTF]), Collège de France - Chaire Chimie des processus biologiques, and Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Electrocatalysis Molecular Modification Heterogeneous Catalysis Carbon Dioxide Inhibition, Heterogeneous Catalysis, [CHIM]Chemical Sciences, QD, General Medicine, General Chemistry, Carbon Dioxide, Q1, Electrocatalysis, Molecular Modification, Catalysis, QD415, Inhibition
Abstract: International audience; Electrochemical CO2 reduction presents a sustainable route to the production of chemicals and fuels. Achieving a narrow product distribution with heterogeneous Cu catalysts is challenging and conventional material modifications offer limited control over selectivity. Here, we show that surface-immobilised molecular species can act as inhibitors for specific carbon products to provide rational control over product 1 distributions. Combined experimental and computational results showed that anchoring of a thiolfunctionalised pyridine on Cu destabilises a surfacebound reaction intermediate to energetically block a COproducing pathway, thereby favouring formate production. The nitrogen atom was shown to be essential to the inhibition mechanism. The ability of molecules to control selectivity through inhibition of specific reaction pathways offers a unique approach to rationally modify heterogeneous catalysts.
Published: 2022
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14. Coupling Electrocatalytic CO 2 Reduction with Thermocatalysis Enables the Formation of a Lactone Monomer

Author: Sarah Lamaison, David W. Wakerley, Thibault Cantat, Emmanuel Nicolas, Ngoc Huan Tran, Louise Ponsard, Marc Fontecave, Chaire Chimie des processus biologiques, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie Moléculaire et de Catalyse pour l'Energie (ex LCCEF) (LCMCE), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), doctoral fellowship from Le Corps des Ponts, des Eaux et des Forêts, Foundation of the Collège de France, Marie Curie Prestige Fellowship, European Project: 768919,CARBON4PUR, European Project: ERC CoG n°818260 ,ReNewHydrides, Collège de France - Chaire Chimie des processus biologiques, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [CHIM.ORGA]Chemical Sciences/Organic chemistry, Electrolytic cell, General Chemical Engineering, [CHIM.CATA]Chemical Sciences/Catalysis, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 7. Clean energy, 01 natural sciences, Combinatorial chemistry, 0104 chemical sciences, Catalysis, Polyester, chemistry.chemical_compound, General Energy, Monomer, chemistry, Environmental Chemistry, General Materials Science, Propylene oxide, 0210 nano-technology, Bimetallic strip, Carbonylation, Faraday efficiency
Abstract: International audience; Carbonylation reactions that generate high-value chemical feedstocks are integral to the formation of many industrially significant compounds. However, these processes require the use of CO, which is invariably derived from fossil-fuelreforming reactions. CO may also be generated through the electroreduction of CO2, but the coupling of these two processes is yet to be considered. Merging electrocatalytic reduction of CO2 to CO with thermocatalytic use of CO would expand the range of the chemicals produced from CO2. This work describes for the first time the development of a system coupling a high-pressure CO2 electrolytic cell containing a bimetallic ZnAg catalyst at the cathode for production of CO with a reactor with a faradaic efficiency of >90 % where high pressure CO is used for carbonylating propylene oxide into β-butyrolactone by thermal catalysis, the latter step having a reaction yield above 80%. While the production of monomers and polymers from CO2 is currently limited to organic carbonates, this strategy opens up the access to lactones from CO2, for the formation of polyesters.
Published: 2021
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15. Dihydrouridine synthesis in tRNAs is under reductive evolution in Mollicutes

Author: Murielle Lombard, Vincent Guérineau, Bruno Faivre, Damien Brégeon, Marc Fontecave, Ludovic Pecqueur, Chau-Duy-Tam Vo, Valérie de Crécy-Lagard, Djemel Hamdane, Catherine Goyenvalle, Soufyan Fakroun, Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL), Sorbonne Université (SU), Chaire Chimie des processus biologiques, Laboratoire de Chimie des Processus Biologiques (LCPB), and Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Models, Molecular, [SDV]Life Sciences [q-bio], Substrate Specificity, Evolution, Molecular, 03 medical and health sciences, chemistry.chemical_compound, 0302 clinical medicine, Bacterial Proteins, RNA, Transfer, Escherichia coli, Cloning, Molecular, Uridine, Molecular Biology, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, Genetics, 0303 health sciences, biology, Cell Biology, biology.organism_classification, Post-transcriptional modification, RNA, Bacterial, chemistry, 030220 oncology & carcinogenesis, Transfer RNA, Mollicutes, Nucleic Acid Conformation, Dihydrouridine, Oxidoreductases, Tenericutes, Research Paper
Abstract: Dihydrouridine (D) is a tRNA-modified base conserved throughout all kingdoms of life and assuming an important structural role. The conserved dihydrouridine synthases (Dus) carries out D-synthesis. DusA, DusB and DusC are bacterial members, and their substrate specificity has been determined in Escherichia coli. DusA synthesizes D20/D20a while DusB and DusC are responsible for the synthesis of D17 and D16, respectively. Here, we characterize the function of the unique dus gene encoding a DusB detected in Mollicutes, which are bacteria that evolved from a common Firmicute ancestor via massive genome reduction. Using in vitro activity tests as well as in vivo E. coli complementation assays with the enzyme from Mycoplasma capricolum (DusB(MCap)), a model organism for the study of these parasitic bacteria, we show that, as expected for a DusB homolog, DusB(MCap) modifies U17 to D17 but also synthetizes D20/D20a combining therefore both E. coli DusA and DusB activities. Hence, this is the first case of a Dus enzyme able to modify up to three different sites as well as the first example of a tRNA-modifying enzyme that can modify bases present on the two opposite sides of an RNA-loop structure. Comparative analysis of the distribution of DusB homologs in Firmicutes revealed the existence of three DusB subgroups namely DusB1, DusB2 and DusB3. The first two subgroups were likely present in the Firmicute ancestor, and Mollicutes have retained DusB1 and lost DusB2. Altogether, our results suggest that the multisite specificity of the M. capricolum DusB enzyme could be an ancestral property.
Published: 2021
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16. Electrochemical CO2 Reduction to Ethanol with Copper-Based Catalysts

Author: José Guillermo Rivera de la Cruz, Charles E. Creissen, Dilan Karapinar, Marc Fontecave, Moritz W. Schreiber, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Total Research and Technology Feluy ( [TRTF])
Subjects: Materials science, Aqueous solution, Renewable Energy, Sustainability and the Environment, Energy Engineering and Power Technology, chemistry.chemical_element, 02 engineering and technology, Overpotential, Raw material, 010402 general chemistry, 021001 nanoscience & nanotechnology, Electrochemistry, 7. Clean energy, 01 natural sciences, Copper, 0104 chemical sciences, Catalysis, Fuel Technology, chemistry, Chemical engineering, Chemistry (miscellaneous), Materials Chemistry, [CHIM]Chemical Sciences, Ethanol fuel, 0210 nano-technology, Faraday efficiency
Abstract: International audience; Electrochemical CO2 reduction presents a sustainable route to storage of intermittent renewable energy. Ethanol is an important target product, which is used as a fuel additive and as a chemical feedstock. However, electrochemical ethanol production is challenging, as it involves the transfer of multiple electrons and protons alongside C–C bond formation. To date, the most commonly employed and effective catalysts are copper-based materials. This Review presents and categorizes the most efficient and selective Cu-based electrocatalysts, which are divided into three main groups: oxide-derived copper, bimetallics, and copper- and nitrogen-doped carbon materials. Only a few other specific examples fall outside this classification. The catalytic performance of these materials for ethanol production in aqueous conditions is discussed in terms of current density, overpotential, and faradaic efficiency. A critical evaluation of the factors that contribute to high performance is provided to aid the design of more efficient catalysts for selective ethanol formation.
Published: 2021
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17. De novo crystal structure determination of double stranded RNA binding domain using only the sulfur anomalous diffraction in SAD phasing

Author: Beatriz G. Guimarães, Béatrice Golinelli-Pimpaneau, Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie des Processus Biologiques (LCPB), and Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: QH301-705.5, S-SAD, Crystal structure, Phase problem, 010402 general chemistry, Sulfur SAD-Phasing, 01 natural sciences, Article, 03 medical and health sciences, Double-stranded RNA binding, chemistry.chemical_compound, Structural Biology, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Biology (General), Molecular Biology, 030304 developmental biology, Multi-orientation, Physics, 0303 health sciences, Resolution (electron density), de novo structure determination, Phaser, Double stranded RNA binding Domain, 0104 chemical sciences, Crystallography, chemistry, X-ray crystallography, Dihydrouridine, Single crystal
Abstract: Single-wavelength anomalous dispersion (SAD)-phasing using sulfur as the unique anomalous scatterer is a powerful method to solve the phase problem in protein crystallography. However, it is not yet widely used by non-expert crystallographers. We report here the structure determination of the double stranded RNA binding domain of human dihydrouridine synthase using the sulfur-SAD method and highly redundant data collected at 1.8 Å (“off-edge”), at which the estimated overall anomalous signal was 1.08%. High multiplicity data were collected on a single crystal rotated along the ϕ or ω axis at different κ angles, with the primary beam intensity being attenuated from 50% to 95%, compared to data collection at 0.98 Å, to reduce radiation damage. SHELXD succeeded to locate 14 out 15 sulfur sites only using the data sets recorded with highest beam attenuation, which provided phases sufficient for structure solving. In an attempt to stimulate the use of sulfur-SAD phasing by a broader community of crystallographers, we describe our experimental strategy together with a compilation of previous successful cases, suggesting that sulfur-SAD phasing should be attempted for determining the de novo structure of any protein with average sulfur content diffracting better than 3 Å resolution., Graphical abstract Image 1, Highlights • The structure of a double stranded RNA binding domain was solved using sulfur-SAD. • X-ray diffraction data were collected on a single crystal in multi-orientations. • Beam attenuation and high data multiplicity were crucial for structure determination. • This paper can guide non-expert crystallographers towards successful S-SAD phasing.
Published: 2021
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18. Structural Evidence for a [4Fe‐5S] Intermediate in the Non‐Redox Desulfuration of Thiouracil

Author: Marc Fontecave, Jonathan Fuchs, Rasa Rutkienė, Rolandas Meškys, Agota Aučynaitė, Ludovic Pecqueur, Matthias Boll, Béatrice Golinelli-Pimpaneau, Jaunius Urbonavičius, Jingjing Zhou, Justas Vaitekūnas, Chaire Chimie des processus biologiques, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Vilnius University [Vilnius], University of Freiburg [Freiburg], and Vilnius Gediminas Technical University
Subjects: [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], 010405 organic chemistry, Stereochemistry, Ligand, chemistry.chemical_element, General Chemistry, Crystal structure, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 01 natural sciences, Sulfur, Redox, Catalysis, Thiouracil, 0104 chemical sciences, chemistry.chemical_compound, chemistry, [CHIM.CRIS]Chemical Sciences/Cristallography, Cluster (physics), [CHIM]Chemical Sciences, Molecule, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM]
Abstract: International audience; We recently discovered a [Fe-S]-containing protein with in vivo thiouracil desulfidase activity called TudS. We report here the crystal structure of TudS, refined at 1.5 Å resolution, which harbors a [4Fe-4S] cluster, bound by three cysteines only. Incubation of TudS crystals with 4-thiouracil trapped the cluster with a hydrosulfide ligand bound to the fourth non-protein-bonded iron, as established by the sulfur anomalous signal. This indicates that a [4Fe-5S] state of the cluster is a catalytic intermediate in the desulfuration reaction. Structural data and site-directed mutagenesis indicate that a water molecule is located next to the hydrosulfide ligand and to two catalytically important residues, Ser101 and Glu45. This information together with modeling studies allow us to propose a mechanism for the unprecedented nonredox enzymatic desulfuration of thiouracil, in which a [4Fe-4S] cluster binds and activates the sulfur atom of the substrate.
Published: 2020
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19. Imidazolium- and Pyrrolidinium-Based Ionic Liquids as Cocatalysts for CO2 Electroreduction in Model Molecular Electrocatalysis

Author: Carlos M. Sánchez-Sánchez, Elli Vichou, Yun Li, Marc Fontecave, Maria Gómez-Mingot, Laboratoire Interfaces et Systèmes Electrochimiques (LISE), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Chaire Chimie des processus biologiques, Laboratoire de Chimie des Processus Biologiques (LCPB), and Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: carbon dioxide reduction, co-catalyst, Chemistry, Supporting electrolyte, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Electrocatalyst, 01 natural sciences, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Catalysis, ionic liquids, chemistry.chemical_compound, General Energy, Chemical engineering, electrostatic interaction, Ionic liquid, electrocatalysis, [CHIM]Chemical Sciences, molecular catalyst, Physical and Theoretical Chemistry, 0210 nano-technology
Abstract: International audience; The structure effect on the role of different ionic liquids (ILs) as simultaneous supporting electrolyte and co-catalyst for CO2 electroreduction in the presence of a model molecular catalyst [Re(bpy)(CO)3Cl] has not been addressed yet. In particular, we varied the nature of the cation, anion and cation alkyl chain by a choice of 5 different ILs, including imidazolium and pyrrolidinium cations and we compared their results to benchmark supporting electrolyte. We report an overpotential diminution of 0.33 V for CO2 to CO conversion in the presence of ILs under CO2 catalytic conditions. We prove the IL cation-dependent overpotential diminution due to the electrostatic stabilization of the negatively-charged active form of the catalyst, being the π-π stacking interaction provided by imidazolium cations responsible for their outstanding performance. Finally, a mechanistic explanation is provided to justify a weaker IL co-catalytic effect when CO2 electroreduction takes place in the presence of a proton source.
Published: 2020
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20. A Single Molecular Stoichiometric P‐Source for Phase‐Selective Synthesis of Crystalline and Amorphous Iron Phosphide Nanocatalysts

Author: Rémi F. André, Grégoire Le Corre, Clément Sanchez, Marc Fontecave, David W. Wakerley, Mohamed Selmane, Hansjörg Grützmacher, Capucine Sassoye, Sophie Carenco, Victor Mougel, Sarah Lamaison, Florian D'Accriscio, Erik Schrader, Chaire Chimie des matériaux hybrides, Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Institut des matériaux de Paris-Centre (IMPC), Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Chaire Chimie des processus biologiques, Laboratoire de Chimie des Processus Biologiques (LCPB), and Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Renewable Energy, Sustainability and the Environment, Energy Engineering and Power Technology, Nanoparticle, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Nanomaterial-based catalyst, 0104 chemical sciences, Amorphous solid, Biomaterials, chemistry.chemical_compound, Iron phosphide, Chemical engineering, chemistry, Phase (matter), Materials Chemistry, [CHIM]Chemical Sciences, Hydrogen evolution, 0210 nano-technology, Stoichiometry, Colloidal synthesis
Abstract: International audience; The formation of iron phosphide nanoparticles (FexP) is a well‐studied process. It usually uses air‐sensitive phosphorus precursors such as n‐trioctylphosphine or white phosphorus. In this study, we report the synthesis and characterization of a remarkably stable tetrakis(acyl)cyclotetraphosphane, P4(MesCO)4. We demonstrate that this compound can be used as a stoichiometric source of P(0) species in order to synthesize FeP and Fe2P nanoparticles at only 250 °C. This tunable process provides a route to monodisperse nanoparticles with different compositions and crystallinities. We combine X‐Ray photoelectron spectroscopy and atomic pair distribution function (PDF) to study the local order and bonding in the amorphous and crystalline materials. We show that crystalline FeP forms via an intermediate amorphous phase (obtained at a lower temperature) that presents local order similar to that of the crystalline sample. We explore their electrocatalytic properties for the hydrogen evolution reaction (HER) in acidic and neutral electrolytes. In both electrolytes, amorphous FeP is a more efficient catalyst than crystalline FeP, itself more efficient than crystalline Fe2P. Our study paves the way for a more systematic investigation of amorphous metal phosphide phases in electrocatalysis. It also shows the beneficial use of PDF on the highly challenging characterization of amorphous nanomaterials.
Published: 2020
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21. Understanding the g-tensors of perchlorotriphenylmethyl and Finland-type trityl radicals

Author: Régis Guillot, Leandro C. Tabares, Paul Demay-Drouhard, H. Y. Vincent Ching, Clotilde Policar, Sun Un, Christophe Decroos, Hélène Bertrand, Yun Li, Laboratoire des biomolécules (LBM UMR 7203), Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Département de Chimie - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Chimie Moléculaire de Paris Centre (FR 2769), Institut de Chimie du CNRS (INC)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), RPE Haut Champ des systèmes biologiques (BHFMR), Département Biochimie, Biophysique et Biologie Structurale (B3S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Moléculaires de Marseille (ISM2), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Chimie Moléculaire de Paris Centre (FR 2769), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département de Chimie - ENS Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC), Université Paris sciences et lettres (PSL), Sorbonne Université (SU), Département de Chimie - ENS Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), and Decroos, Christophe
Subjects: 010405 organic chemistry, Physics, Radical, Heteroatom, General Physics and Astronomy, Protonation, 010402 general chemistry, 01 natural sciences, 0104 chemical sciences, law.invention, Chemistry, chemistry.chemical_compound, Crystallography, Delocalized electron, chemistry, law, [CHIM] Chemical Sciences, [CHIM]Chemical Sciences, Carboxylate, Physical and Theoretical Chemistry, Methylene, Spin (physics), Electron paramagnetic resonance
Abstract: International audience; The 285 GHz EPR spectra of perchlorotriphenylmethyl and tetrathiatriarylmethyl radicals in frozen solution have been accurately measured. The relationship between their molecular structures and their g-tensors has been investigated with the aid of DFT calculations, revealing that the degree of spin density delocalization away from the central methylene carbon is an important determining factor of the g-anisotropy. In particular, the small amount of spin densities on the Cl or S heteroatoms at the 2 and 6 positions with respect to the central carbon have the strongest influence. Furthermore, the amount of spin densities on these heteroatoms and thus the anisotropy can be modulated by the protonation (esterification) state of the carboxylate groups at the 4 position. These results provide unique insights into the g-anisotropy of persistent trityl radicals and how it can be tuned.
Published: 2020
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22. Understanding the Photocatalytic Reduction of CO 2 with Heterometallic Molybdenum(V) Phosphate Polyoxometalates in Aqueous Media

Author: Youven Benseghir, Albert Solé-Daura, Pierre Mialane, Jérôme Marrot, Lauren Dalecky, Solène Béchu, Mathieu Frégnaux, Maria Gomez-Mingot, Marc Fontecave, Caroline Mellot-Draznieks, Anne Dolbecq, Institut Lavoisier de Versailles (ILV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie et de Biochimie Pharmacologiques et Toxicologiques (LCBPT - UMR 8601), and Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)
Subjects: [CHIM]Chemical Sciences, 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 0210 nano-technology, 01 natural sciences, Catalysis, ComputingMilieux_MISCELLANEOUS, 0104 chemical sciences
Abstract: International audience
Published: 2022
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23. Influence of the protein distribution of maize endosperm on ruminal starch degradability

Author: Jacques Landry, Brigitte Michalet-Doreau, C. Philippeau, ProdInra, Migration, Station de recherches sur la nutrition des herbivores, Institut National de la Recherche Agronomique (INRA), Chimie Biologique (UCB), Institut National de la Recherche Agronomique (INRA)-Institut National Agronomique Paris-Grignon (INA P-G), Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie des processus Biologiques (LCPB), and Collège de France (CdF)
Subjects: Starch, [SDV]Life Sciences [q-bio], PROTEIN, Biology, Polysaccharide, Endosperm, Rumen, chemistry.chemical_compound, DIGESTION, [SDV.IDA]Life Sciences [q-bio]/Food engineering, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, Food science, ComputingMilieux_MISCELLANEOUS, 2. Zero hunger, chemistry.chemical_classification, Nutrition and Dietetics, Starch degradation, [SDV.IDA] Life Sciences [q-bio]/Food engineering, Protein distribution, GENOTYPE, Biochemistry, chemistry, RUMEN, Plant protein, STARCH, Digestion, Agronomy and Crop Science, MAIZE, Food Science, Biotechnology
Abstract: This study was aimed at determining the influence of the protein distribution of maize endosperm on ruminal starch degradation using 14 maizes differing in endosperm texture (eight dent and six flint maizes). Ruminal starch degradability was determined by an in situ technique on ground samples with a particle size of 3 mm. The distribution of endosperm proteins was assayed by a method based on their differential solubilities in solvents. The (α,β,δ)-zeins and the true glutelins were the predominant proteins in the endosperm. The (α,β,δ)-zeins (66.1 and 70.1 g kg−1 of recovered protein for dent and flint types respectively) and the true glutelins (21.8 and 18.4 g kg−1 of recovered protein for dent and flint types respectively) were related to the vitreousness, ie the ratio of vitreous to floury endosperm. Ruminal starch degradability averaged 619 and 462 g kg−1 for dent and flint maizes respectively. It was correlated negatively with the (α,β,δ)-zeins and positively with the true glutelins. The (α,β,δ)-zeins located in the protein bodies should limit the accessibility of starch granules to ruminal micro-organisms and, as a consequence, the ruminal starch degradability. © 2000 Society of Chemical Industry
Published: 2000
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24. Ultrafast Dynamics of Fully Reduced Flavin in Catalytic Structures of Thymidylate Synthase ThyX

Author: Murielle Lombard, Fabien Lacombat, Pascal Plaza, Djemel Hamdane, Nadia Dozova, Processus d'Activation Sélective par Transfert d'Energie Uni-électronique ou Radiatif (UMR 8640) (PASTEUR), Département de Chimie - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie des Processus Biologiques (LCPB), and Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Dinitrocresols, General Physics and Astronomy, Flavin group, Molecular Dynamics Simulation, 010402 general chemistry, Photochemistry, 01 natural sciences, Thymidylate synthase, Cofactor, 03 medical and health sciences, chemistry.chemical_compound, Thermotoga maritima, Physical and Theoretical Chemistry, Methylene, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], 030304 developmental biology, Flavin adenine dinucleotide, 0303 health sciences, biology, Molecular Structure, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], Substrate (chemistry), Thymidylate Synthase, Conical intersection, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, chemistry, biology.protein, Biocatalysis, Oxidation-Reduction, Methyl group
Abstract: International audience; Thymidylate is a vital DNA precursor synthesized by thymidylate synthases. ThyX is a flavin-dependent thymidylate synthase found in several human pathogens and absent in humans, which makes it a potential target for antimicrobial drugs. This enzyme methylates the 2'-deoxyuridine 5'-monophosphate (dUMP) to 2'-deoxythymidine 5'-monophosphate (dTMP) using a reduced flavin adenine dinucleotide (FADH-) as prosthetic group and (6R)-N5,N10-methylene-5,6,7,8-tetrahydrofolate (CH2THF) as a methylene donor. Recently, it was shown that ThyX-catalyzed reaction is a complex process wherein FADH- promotes both methylene transfer and reduction of the transferred methylene into a methyl group. Here, we studied the dynamic and photophysics of FADH- bound to ThyX, in several substrate-binding states (no substrate, in the presence of dUMP or folate or both) by femtosecond transient absorption spectroscopy. This methodology provides valuable information about the ground-state configuration of the isoalloxazine moiety of FADH- and the rigidity of its local environment, through spectra shape and excited-state lifetime parameters. In the absence of substrate, the environment of FADH- in ThyX is only mildly more constrained than that of free FADH- in solution. The addition of dUMP however narrows the distribution of ground-state configurations and increases the constraints on the butterfly bending motion in the excited state. Folate binding results in the selection of new ground-state configurations, presumably located at a greater distance from the conical intersection where excited-state decay occurs. When both substrates are present, the ground-state configuration appears on the contrary rather limited to a geometry close to the conical intersection, which explains the relatively fast excited-state decay (100 ps on the average), even if the environment of the isoalloxazine is densely packed. Hence, although the environment of the flavin is dramatically constrained, FADH- retains a dynamic necessary to shuttle carbon from folate to dUMP. Our study demonstrates the high sensitivity of FADH- photophysics to the constraints exerted by its immediate surroundings.
Published: 2021
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25. Structural Insights into the Dimeric Form of Bacillus subtilis RNase Y Using NMR and AlphaFold

Author: Nelly Morellet, Pierre Hardouin, Nadine Assrir, Carine van Heijenoort, Béatrice Golinelli-Pimpaneau, Institut de Chimie des Substances Naturelles (ICSN), Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Marrow Adiposity & Bone Lab - Adiposité Médullaire et Os - ULR 4490 (MABLab (ex-pmoi)), Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Centre Hospitalier Régional Universitaire [Lille] (CHRU Lille), Université du Littoral Côte d'Opale (ULCO), Laboratoire de Chimie des Processus Biologiques (LCPB), and Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: RNase Y, dimerization, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], coiled-coil, ribonuclease, NMR, AlphaFold, structure, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Molecular Biology, Biochemistry
Abstract: International audience; RNase Y is a crucial component of genetic translation, acting as the key enzyme initiating mRNA decay in many Gram-positive bacteria. The N-terminal domain of Bacillus subtilis RNase Y (Nter-BsRNaseY) is thought to interact with various protein partners within a degradosome complex. Bioinformatics and biophysical analysis have previously shown that Nter-BsRNaseY, which is in equilibrium between a monomeric and a dimeric form, displays an elongated fold with a high content of α-helices. Using multidimensional heteronuclear NMR and AlphaFold models, here, we show that the Nter-BsRNaseY dimer is constituted of a long N-terminal parallel coiled-coil structure, linked by a turn to a C-terminal region composed of helices that display either a straight or bent conformation. The structural organization of the N-terminal domain is maintained within the AlphaFold model of the full-length RNase Y, with the turn allowing flexibility between the N- and C-terminal domains. The catalytic domain is globular, with two helices linking the KH and HD modules, followed by the C-terminal region. This latter region, with no function assigned up to now, is most likely involved in the dimerization of B. subtilis RNase Y together with the N-terminal coiled-coil structure.
Published: 2022
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26. Metal–Metal Synergy in Well-Defined Surface Tantalum–Iridium Heterobimetallic Catalysts for H/D Exchange Reactions

Author: Sébastien Lassalle, Laurent Veyre, Anne Lesage, Tanya K. Todorova, Chloé Thieuleux, Ribal Jabbour, Clément Camp, David Gajan, Pauline Schiltz, Pierrick Berruyer, Laboratoire de Chimie, Catalyse, Polymères et Procédés, R 5265 (C2P2), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre de RMN à très hauts champs de Lyon (CRMN), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université de Lyon-Université de Lyon-École Supérieure de Chimie Physique Électronique de Lyon (CPE)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL)
Subjects: H/D exchange, Alkane, chemistry.chemical_classification, tantalum, Chemistry, Surface organometallic chemistry, Tantalum, hydrides, chemistry.chemical_element, General Chemistry, iridium, 010402 general chemistry, 01 natural sciences, Biochemistry, Catalysis, 0104 chemical sciences, Colloid and Surface Chemistry, Polymer chemistry, early/late heterobimetallics, [CHIM]Chemical Sciences, Metal metal, Iridium, Well-defined
Abstract: International audience; A novel heterobimetallic tantalum/iridium hydrido complex, [{Ta(CH2 t Bu)3}{IrH2(Cp*)}] 1, featuring a very short metal-metal bond, has been isolated through an original alkane elimination route from Ta(CH t Bu)(CH2 t Bu)3 and Cp*IrH4. This molecular precursor has been used to synthesize well-defined silica-supported low-coordinate heterobime-tallic hydrido species [≡SiOTa(CH2 t Bu)2{IrH2(Cp*)}] 5 and [≡SiOTa(CH2 t Bu)H{IrH2(Cp*)}] 6 using a surface organometallic chemistry approach (SOMC). The SOMC methodology prevents undesired dimerization as encountered in solution and leading to a tetranuclear species [{Ta(CH2 t Bu)2}(Cp*IrH)]2, 4. This approach therefore allows access to unique low-coordinate species not attainable in solution. These original supported Ta/Ir species exhibit drastically enhanced catalytic performances in H/D exchange reactions with respect to (i) monometallic analogues as well as (ii) homogeneous systems. In particular, material 6 promotes the H/D exchange between fluorobenzene and C6D6 or D2 as deuterium sources with excellent productivity (TON up to 1422; TOF up to 23.3 h-1) under mild conditions (25°C, subatmospheric D2 pressure) without any additives.
Published: 2019
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27. Bio-inspired hydrophobicity promotes CO2 reduction on a Cu surface

Author: David W. Wakerley, Sarah Lamaison, Marc Fontecave, François Ozanam, Philippe Marcus, Nicolas Menguy, Victor Mougel, Dimitri Mercier, Chaire Chimie des processus biologiques, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique de la matière condensée (LPMC), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche de Chimie Paris (IRCP), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ministère de la Culture (MC), Collège de France - Chaire Chimie des processus biologiques, Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Ministère de la Culture (MC)
Subjects: chemistry.chemical_classification, Aqueous solution, Mechanical Engineering, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Electrochemistry, Heterogeneous catalysis, Electrocatalyst, 01 natural sciences, 0104 chemical sciences, Catalysis, Hydrocarbon, chemistry, Chemical engineering, Mechanics of Materials, General Materials Science, Wetting, [CHIM.OTHE]Chemical Sciences/Other, 0210 nano-technology, Selectivity
Abstract: The aqueous electrocatalytic reduction of CO2 into alcohol and hydrocarbon fuels presents a sustainable route towards energy-rich chemical feedstocks. Cu is the only material able to catalyse the substantial formation of multicarbon products (C2/C3), but competing proton reduction to hydrogen is an ever-present drain on selectivity. Here, a superhydrophobic surface was generated by 1-octadecanethiol treatment of hierarchically structured Cu dendrites, inspired by the structure of gas-trapping cuticles on subaquatic spiders. The hydrophobic electrode attained a 56% Faradaic efficiency for ethylene and 17% for ethanol production at neutral pH, compared to 9% and 4% on a hydrophilic, wettable equivalent. These observations are assigned to trapped gases at the hydrophobic Cu surface, which increase the concentration of CO2 at the electrode–solution interface and consequently increase CO2 reduction selectivity. Hydrophobicity is thus proposed as a governing factor in CO2 reduction selectivity and can help explain trends seen on previously reported electrocatalysts. Aqueous electrocatalytic reduction of CO2 into alcohol and hydrocarbon fuels is a sustainable route towards energy-rich chemical feedstocks. A superhydrophobic surface of hierarchically structured Cu dendrites exhibits a significant increase in CO2 reduction selectivity.
Published: 2019
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28. Lamina Cribrosa Curvature in Healthy Korean Eyes

Author: Tan, Nicholas, Tham, Yih-Chung, Thakku, Sri Gowtham, Wang, Xiaofei, Baskaran, Mani, Tan, Marcus, Mari, Jean-Martial, Strouthidis, NIcholas, Aung, Tin, Cheng, Ching-Yu, Lee, Seung Hyen, Kim, Tae-Woo, Lee, Eun Ji, Girard, Michaël, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Géopôle du Pacifique Sud (GePaSUD), Université de la Polynésie Française (UPF), and Duke-NUS Medical School [Singapore]
Subjects: Adult, Male, 0301 basic medicine, medicine.medical_specialty, Lamina, genetic structures, Optic Disk, Glaucoma, lcsh:Medicine, Curvature, Article, Young Adult, 03 medical and health sciences, 0302 clinical medicine, Optical coherence tomography, Ophthalmology, [INFO.INFO-IM]Computer Science [cs]/Medical Imaging, Humans, Medicine, lcsh:Science, ComputingMilieux_MISCELLANEOUS, Aged, Multidisciplinary, medicine.diagnostic_test, business.industry, Healthy population, lcsh:R, Healthy subjects, Middle Aged, medicine.disease, eye diseases, 030104 developmental biology, medicine.anatomical_structure, Biological Variation, Population, Population Surveillance, Female, lcsh:Q, Enhanced depth imaging, sense organs, Factor Analysis, Statistical, business, Tomography, Optical Coherence, 030217 neurology & neurosurgery, Optic disc
Abstract: Given that posterior bowing of the lamina cribrosa (LC) is a principle event in the development of glaucomatous damage, assessment of the LC morphology may have clinical utility in diagnosing and managing glaucoma patients. LC curvature has been suggested as an index to evaluate the LC morphology. To apply LC morphology in clinical practice, it is necessary to know normal profiles of LC curvature in healthy population. This study was performed to investigate the characteristics of LC curvature in healthy eyes using enhanced depth imaging spectral-domain optical coherence tomography in a total of 250 eyes of 125 healthy Korean subjects. The lamina cribrosa curvature index (LCCI) values at seven locations spaced equidistantly across the vertical optic disc diameter were measured on serial horizontal B-scan images. The mean value of the seven measurements was defined as the average LCCI. The average LCCI was 7.46 ± 1.22 (range, 4.29–10.48) and did not differ significantly between the right and left eyes. There was a strong inter-eye correlation within subjects. LCCI was significantly larger in eyes with shorter axial length (P
Published: 2019
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29. Molecular basis for transfer RNA recognition by the double-stranded RNA-binding domain of human dihydrouridine synthase 2

Author: Charles Bou-Nader, Pierre Barraud, Ludovic Pecqueur, Javier Pérez, Christophe Velours, William Shepard, Marc Fontecave, Carine Tisné, Djemel Hamdane, Chaire Chimie des processus biologiques, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de cristallographie et RMN biologiques (LCRB - UMR 8015), Université Paris Descartes - Paris 5 (UPD5)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Expression Génétique Microbienne (EGM (UMR_8261 / FRE_3630)), Institut de biologie physico-chimique (IBPC (FR_550)), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Collège de France (CdF)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris Descartes - Paris 5 (UPD5), Institut de biologie physico-chimique (IBPC), Université Paris-Sud - Paris 11 (UP11)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Collège de France - Chaire Chimie des processus biologiques, and Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Models, Molecular, 0303 health sciences, Binding Sites, Protein Conformation, RNA Splicing, 03 medical and health sciences, 0302 clinical medicine, Protein Domains, RNA, Transfer, X-Ray Diffraction, Scattering, Small Angle, RNA and RNA-protein complexes, Genetics, Humans, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Amino Acid Sequence, RNA Editing, Oxidoreductases, 030217 neurology & neurosurgery, Protein Binding, RNA, Double-Stranded, 030304 developmental biology
Abstract: International audience; Double stranded RNA-binding domain (dsRBD) is a ubiquitous domain specialized in the recognition of double-stranded RNAs (dsRNAs). Present in many proteins and enzymes involved in various functional roles of RNA metabolism, including RNA splicing, editing, and transport, dsRBD generally binds to RNAs that lack complex structures. However, this belief has recently been challenged by the discovery of a dsRBD serving as a major tRNA binding module for human dihydrouridine synthase 2 (hDus2), a flavoenzyme that catalyzes synthesis of dihydrouri-dine within the complex elbow structure of tRNA. We here unveil the molecular mechanism by which hDus2 dsRBD recognizes a tRNA ligand. By solving the crystal structure of this dsRBD in complex with a dsRNA together with extensive characterizations of its interaction with tRNA using mutagenesis, NMR and SAXS, we establish that while hDus2 dsRBD retains a conventional dsRNA recognition capability, the presence of an N-terminal extension appended to the canonical domain provides additional residues for binding tRNA in a structure-specific mode of action. Our results support that this extension represents a feature by which the dsRBD specializes in tRNA biology and more broadly highlight the importance of structural appendages to canonical domains in promoting the emergence of functional diversity.
Published: 2019
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30. Ultrafast photoinduced flavin dynamics in the unusual active site of the tRNA methyltransferase TrmFO

Author: Fabien Lacombat, Nadia Dozova, Djemel Hamdane, Charles Bou-Nader, Pascal Plaza, Processus d'Activation Sélective par Transfert d'Energie Uni-électronique ou Radiatif (UMR 8640) (PASTEUR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Département de Chimie - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie des Processus Biologiques (LCPB), and Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Models, Molecular, Stereochemistry, Stacking, General Physics and Astronomy, Flavoprotein, 02 engineering and technology, Flavin group, 010402 general chemistry, 01 natural sciences, Cofactor, Deprotonation, Flavins, Moiety, heterocyclic compounds, Amino Acid Sequence, Cysteine, Physical and Theoretical Chemistry, tRNA Methyltransferases, Binding Sites, biology, Chemistry, Adenine, TRNA Methyltransferase, Active site, Photochemical Processes, 021001 nanoscience & nanotechnology, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, enzymes and coenzymes (carbohydrates), Kinetics, 13. Climate action, Flavin-Adenine Dinucleotide, biology.protein, bacteria, Tyrosine, 0210 nano-technology, Oxidation-Reduction, Bacillus subtilis, Protein Binding
Abstract: Flavoproteins often stabilize their flavin coenzyme by stacking interactions involving the isoalloxazine moiety of the flavin and an aromatic residue from the apoprotein. The bacterial FAD and folate-dependent tRNA methyltransferase TrmFO has the unique property of stabilizing its FAD coenzyme by an unusual H-bond-assisted π-π stacking interaction, involving a conserved tyrosine (Y346 in Bacillus subtilis TrmFO, BsTrmFO), the isoalloxazine of FAD and the backbone of a catalytic cysteine (C53). Here, the interaction between FAD and Y346 has been investigated by measuring the photoinduced flavin dynamics of BsTrmFO in the wild-type (WT) protein, C53A and several Y346 mutants by ultrafast transient absorption spectroscopy. In C53A, the excited FAD very rapidly (0.43 ps) abstracts an electron from Y346, yielding the FAD˙-/Y346OH˙+ radical pair, while relaxation of the local environment (1.3 ps) of the excited flavin produces a slight Stokes shift of its stimulated emission band. The radical pair then decays via charge recombination, mostly in 3-4 ps, without any deprotonation of the Y346OH˙+ radical. Presumably, the H-bond between Y346 and the amide group of C53 increases the pKa of Y346OH˙+ and slows down its deprotonation. The dynamics of WT BsTrmFO shows additional slow decay components (43 and 700 ps), absent in the C53A mutant, assigned to excited FADox populations not undergoing fast photoreduction. Their presence is likely due to a more flexible structure of the WT protein, favored by the presence of C53. Interestingly, mutations of Y346 canceling its electron donating character lead to multiple slower quenching channels in the ps-ns regime. These channels are proposed to be due to electron abstraction either (i) from the adenine moiety of FAD, a distribution of the isoalloxazine-adenine distance in the absence of Y346 explaining the multiexponential decay, or (ii) from the W286 residue, possibly accounting for one of the decays. This work supports the idea that H-bond-assisted π-π stacking controls TrmFO's active site dynamics, required for competent orientation of the reactive centers during catalysis.
Published: 2019
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31. Benchmarking of oxygen evolution catalysts on porous nickel supports

Author: Huan Ngoc Tran, Charles E. Creissen, Marc Fontecave, Dilan Karapinar, Adèle Peugeot, Moritz W. Schreiber, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Total Research and Technology Feluy ( [TRTF]), Chaire Chimie des processus biologiques, and Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, anode, solar fuels, chemistry.chemical_element, 02 engineering and technology, 010402 general chemistry, Electrocatalyst, 01 natural sciences, Catalysis, law.invention, law, electrocatalysis, [CHIM]Chemical Sciences, transition metal oxides, benchmarking, Porosity, Electrolysis, oxygen evolution catalyst, Ni foam, Oxygen evolution, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Anode, Nickel, General Energy, Chemical engineering, chemistry, water oxidation, CO2 reduction, Leaching (metallurgy), 0210 nano-technology
Abstract: International audience; Active and inexpensive oxygen evolution reaction (OER) electrocatalysts are needed for energy-efficient electrolysis applications. Objective comparison between OER catalysts has been blurred by the use of different supports and methods to evaluate performance. Here, we selected nine highly active transition-metal-based catalysts and described their synthesis, using a porous nickel foam and a new Ni-based dendritic material as the supports. We designed a standardized protocol to characterize and compare the catalysts in terms of structure, activity, density of active sites, and stability. NiFeSe- and CoFeSe-derived oxides showed the highest activities on our dendritic support, with low overpotentials of η100 ≈ 247 mV at 100 mA cm–2 in 1 M KOH. Stability evaluation showed no surface leaching for 8 h of electrolysis. This work highlights the most active anode materials and provides an easy way to increase the geometric current density of a catalyst by tuning the porosity of its support.
Published: 2021
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32. Iron–sulfur biology invades tRNA modification: the case of U34 sulfuration

Author: Karolina Podskoczyj, Christophe Velours, Grazyna Leszczynska, Jingjing Zhou, Marine Lénon, Marc Fontecave, Jean-Luc Ravanat, Béatrice Golinelli-Pimpaneau, Nadia Touati, Frédéric Barras, Chimie Interface Biologie pour l’Environnement, la Santé et la Toxicologie (CIBEST ), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Adaptation au stress et Métabolisme chez les entérobactéries - Stress adaptation and metabolism in enterobacteria (SAMe), Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), Département Interfaces pour l'énergie, la Santé et l'Environnement (DIESE), Institut de Recherche de Chimie Paris (IRCP), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ministère de la Culture (MC), Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), University of Lódź, ANR-11-LABX-0011,DYNAMO,Dynamique des membranes transductrices d'énergie : biogénèse et organisation supramoléculaire.(2011), ANR-10-LABX-0062,IBEID,Integrative Biology of Emerging Infectious Diseases(2010), Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Ministère de la Culture (MC)
Subjects: chemistry.chemical_classification, 0303 health sciences, TRNA modification, AcademicSubjects/SCI00010, Nucleic Acid Enzymes, [CHIM.ORGA]Chemical Sciences/Organic chemistry, [SDV]Life Sciences [q-bio], 030302 biochemistry & molecular biology, Mutagenesis, Biology, medicine.disease_cause, Uridine, 03 medical and health sciences, chemistry.chemical_compound, Enzyme, Biosynthesis, chemistry, Biochemistry, Transfer RNA, Genetics, medicine, Escherichia coli, Nucleoside, 030304 developmental biology
Abstract: Sulfuration of uridine 34 in the anticodon of tRNAs is conserved in the three domains of life, guaranteeing fidelity of protein translation. In eubacteria, it is catalyzed by MnmA-type enzymes, which were previously concluded not to depend on an iron–sulfur [Fe–S] cluster. However, we report here spectroscopic and iron/sulfur analysis, as well as in vitro catalytic assays and site-directed mutagenesis studies unambiguously showing that MnmA from Escherichia coli can bind a [4Fe–4S] cluster, which is essential for sulfuration of U34-tRNA. We propose that the cluster serves to bind and activate hydrosulfide for nucleophilic attack on the adenylated nucleoside. Intriguingly, we found that E. coli cells retain s2U34 biosynthesis in the ΔiscUA ΔsufABCDSE strain, lacking functional ISC and SUF [Fe–S] cluster assembly machineries, thus suggesting an original and yet undescribed way of maturation of MnmA. Moreover, we report genetic analysis showing the importance of MnmA for sustaining oxidative stress.
Published: 2021
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33. ipaA triggers vinculin oligomerization to strengthen cell adhesion during Shigella invasion

Author: Lars Malmström, Julia Chamot-Rooke, Hamed Khazad, Atef Asnacios, Christian Malosse, Delphine Javelaud, Benjamim Cocom-Chan, Jacques Fattaccioli, Charles Bou-Nader, Chakir Bello, Marc Fontecave, Daniel Isui Aguilar Salvador, Alain Mauviel, Bilal Mazhar, Diogo Borges-Lima, Guy Tran Van Nhieu, Cesar Valencia-Gallardo, Nicole Quenech’Du, Centre interdisciplinaire de recherche en biologie (CIRB), Labex MemoLife, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Collège de France (CdF (institution))-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL), Swiss Institute of Bioinformatics [Lausanne] (SIB), Université de Lausanne = University of Lausanne (UNIL), Universität Zürich [Zürich] = University of Zurich (UZH), Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Spectrométrie de Masse pour la Biologie – Mass Spectrometry for Biology (UTechS MSBio), Institut Pasteur [Paris] (IP)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Signalisation, radiobiologie et cancer, Institut Curie [Paris]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Processus d'Activation Sélective par Transfert d'Energie Uni-électronique ou Radiatif (UMR 8640) (PASTEUR), Département de Chimie - ENS Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Matière et Systèmes Complexes (MSC), Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Lund University [Lund], Institut Pierre-Gilles de Gennes pour la Microfluidique, Matière et Systèmes Complexes (MSC (UMR_7057)), Alain, Mauviel, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université de Lausanne (UNIL), Institut Pasteur [Paris]-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), and Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)
Subjects: 0303 health sciences, biology, Effector, Chemistry, Allosteric regulation, [SDV.CAN]Life Sciences [q-bio]/Cancer, Adhesion, macromolecular substances, Vinculin, Cell biology, Focal adhesion, 03 medical and health sciences, 0302 clinical medicine, [SDV.CAN] Life Sciences [q-bio]/Cancer, biology.protein, Mechanotransduction, Cell adhesion, 030217 neurology & neurosurgery, Actin, 030304 developmental biology
Abstract: The Shigella effector IpaA co-opts the focal adhesion protein vinculin to promote bacterial invasion. Here, we show that IpaA triggers an unreported mode of vinculin activation through the cooperative binding of its three vinculin-binding sites (VBSs) leading to vinculin oligomerization via its D1 and D2 head subdomains and highly stable adhesions resisting actin relaxing drugs. Using cross-linking mass spectrometry, we found that while IpaA VBSs1-2 bound to D1, IpaA VBS3 interacted with D2, a subdomain masked to other known VBSs. Structural modeling indicated that as opposed to canonical activation linked to interaction with D1, these combined VBSs interactions triggered major allosteric changes leading to D1D2 oligomerization. A cysteine-clamp preventing these changes and D1D2 oligomerization impaired growth of vinculin microclusters and cell adhesion. We propose that D1D2-mediated vinculin oligomerization occurs during the maturation of adhesion structures to enable the scaffolding of high-order vinculin complexes, and is triggered by Shigella IpaA to promote bacterial invasion in the absence of mechanotransduction.SummaryThe Shigella IpaA effector binds to cryptic vinculin sites leading to oligomerization via its head domain. This vinculin oligomerization mode appears required for the maturation and strengthening of cell adhesion but is co-opted by invasive bacteria independent of actomyosin contractility.
Published: 2021

34. Impact of Organic Templates on the Selective Formation of Zeolite Oligomers

Author: Carine Michel, Thuat T. Trinh, Philippe Sautet, Carlos Nieto-Draghi, Marine Ciantar, Caroline Mellot-Draznieks, IFP Energies nouvelles (IFPEN), Laboratoire de Chimie - UMR5182 (LC), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon)-Institut de Chimie du CNRS (INC), Department of Chemical and Biomolecular Engineering [Los Angeles], University of California [Los Angeles] (UCLA), University of California-University of California, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and University of California (UC)-University of California (UC)
Subjects: Materials science, templates, non covalent interactions, 02 engineering and technology, Ring (chemistry), 010402 general chemistry, DFT calculations, Oligomer, 01 natural sciences, Catalysis, chemistry.chemical_compound, Adsorption, Computational chemistry, kMC method, [CHIM]Chemical Sciences, Kinetic Monte Carlo, Zeolite, 010405 organic chemistry, Organic Chemistry, General Chemistry, General Medicine, [CHIM.CATA]Chemical Sciences/Catalysis, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Template, chemistry, Intramolecular force, Chemical Sciences, zeolite oligomerisation, 0210 nano-technology
Abstract: International audience; Zeolites are essential materials to industry due to their adsorption and catalytic properties. The best current approach to prepare a targeted zeolite still relies on trial and error's synthetic procedures since a rational understanding of the impact of synthesis variables on the final structures is still missing. To discern the role of a variety of organic templates, we perform simulations of the early stages of condensation of silica oligomers by combining DFT, Brønsted-Evans-Polanyi relationships and kinetic Monte Carlo simulations. We investigate an extended reaction path mechanism including 258 equilibrium reactions and 242 chemical species up to silica octamers, comparing the computed concentrations of Si oligomers with 29SI NMR experimental data. The effect of the templating agent is linked to the modification of the intramolecular H-bond network in the growing oligomer, which produces higher concentration of 4-membered ring intermediates, precursors of the key double-four ring building blocks present on more than 39 known zeolite topologies.
Published: 2021
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35. Temperature sensors based on europium polyoxometalate and mesoporous terbium metal–organic framework

Author: Olivier Oms, Caroline Mellot-Draznieks, Cédric Viravaux, Lucas Busson, Emma Nassar, Rémi Dessapt, Hélène Serier-Brault, Anne Dolbecq, Pierre Mialane, Institut Lavoisier de Versailles (ILV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut des Matériaux Jean Rouxel (IMN), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-Université de Nantes (UN), ANR-11-IDEX-0003,IPS,Idex Paris-Saclay(2011), and ANR-11-LABX-0039,CHARMMMAT,CHimie des ARchitectures MoléculairesMultifonctionnelles et des MATériaux(2011)
Subjects: Lanthanide, Materials science, Hydrogen bond, Inorganic chemistry, chemistry.chemical_element, Terbium, 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 7. Clean energy, 01 natural sciences, 0104 chemical sciences, chemistry, Polyoxometalate, Materials Chemistry, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Molecule, Metal-organic framework, 0210 nano-technology, Mesoporous material, Europium
Abstract: International audience; The first example of ratiometric luminescent thermometers based on lanthanide molecular species encapsulated in a lanthanide metal–organic framework (MOF) is reported. In EuW10@Tb-TATB, the [EuW10O36]9− polyoxometalate (POM) is incorporated into the cavities of the mesoporous terbium MOF Tb-TATB with two different POM loadings (9.1 and 19.5 wt%). Eu3+ and Tb3+ ions of the POM and MOF, respectively, act as dual emitters. Optical measurements evidence efficient Tb3+-to-Eu3+ energy transfer, suggesting that the EuW10 units are close to terbium centers. These observations are supported by computational investigations whereby a favored localisation of the EuW10 POM in the MOF's pores is found close to Tb-centers evidencing hydrogen bond type interactions between terminal oxygen atoms of the POM and Tb-coordinated water molecules. The reported materials act as temperature sensors in the physiological domain, exhibiting high relative thermal sensitivities of 2.68% K−1 and 2.37% K−1 at 300 K for the 9.1 wt% and 19.5 wt% composites, respectively, with a thermal uncertainty of 0.09 K.
Published: 2021
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36. Heterogenization of a Molecular Ni Catalyst within a Porous Macroligand for the Direct C-H Arylation of Heteroarenes

Author: Elsje Alessandra Quadrelli, Mathis Duguet, Partha Samanta, Chantal Lorentz, Florian M. Wisser, Caroline Mellot-Draznieks, Marcelo Alves-Favaro, Gaëlle Hisler, Alisa Ranscht, Rémy Rajapaksha, Jérôme Canivet, Yorck Mohr, IRCELYON-Ingéniérie, du matériau au réacteur (ING), Institut de recherches sur la catalyse et l'environnement de Lyon (IRCELYON), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), IRCELYON-Catalyse Hétérogène pour la Transition Energétique (CATREN), IRCELYON-RMN (RMN), Laboratoire de Chimie des Processus Biologiques (LCPB), and Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: inorganic chemicals, chemistry.chemical_element, porous polymers, LiHMDS, 010402 general chemistry, Heterogeneous catalysis, 01 natural sciences, Catalysis, macroligand, chemistry.chemical_compound, Bipyridine, Polymer chemistry, Thiophene, cross-coupling, 010405 organic chemistry, Hydride, [CHIM.ORGA]Chemical Sciences/Organic chemistry, nickel complex, General Chemistry, Nuclear magnetic resonance spectroscopy, [CHIM.CATA]Chemical Sciences/Catalysis, 0104 chemical sciences, Turnover number, Nickel, chemistry, heterobiaryl, C−H arylation
Abstract: International audience; Direct C–H functionalization catalyzed by a robust and recyclable heterogeneous catalyst is highly desirable for sustainable fine chemical synthesis. Bipyridine units covalently incorporated into the backbone of a porous organic polymer were used as a porous macroligand for the heterogenization of a molecular nickel catalyst. A controlled nickel loading within the porous macroligand is achieved, and the nickel coordination to the bipyridine (bpy) sites is assessed at the molecular level using IR and solid-state NMR spectroscopy. The heterogenized Ni-bpy catalyst was successfully applied to the direct and fully selective C2 arylation of benzothiophenes, thiophene, and selenophene, as well as for the arylation of free NH-indole. Recyclability of the catalyst was achieved by employing hydride activators to reach a cumulative turnover number of more than 300 after seven cycles of catalysis, which corresponds to a total productivity of 12 g of 2-phenylbenzothiophene, chosen as model target biaryl, per gram of catalyst.
Published: 2021
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37. Crystal Structure of Two Anti-Porphyrin Antibodies with Peroxidase Activity

Author: Jean-Didier Maréchal, Victor Muñoz Robles, Béatrice Golinelli-Pimpaneau, Amel Bahloul, Marie-Agnès Sari, Jean-Pierre Mahy, Universitat Autònoma de Barcelona (UAB), Laboratoire d'Enzymologie et Biochimie Structurales, Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie et de Biochimie Pharmacologiques et Toxicologiques (LCBPT - UMR 8601), Université Paris Descartes - Paris 5 (UPD5)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICCMO), Université Paris-Sud - Paris 11 (UP11), Laboratoire de Chimie des Processus Biologiques (LCPB), and Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Models, Molecular, Protein Conformation, lcsh:Medicine, Crystallography, X-Ray, 01 natural sciences, Biochemistry, Biophysics Simulations, chemistry.chemical_compound, Mice, Protein structure, Biomacromolecule-Ligand Interactions, Enzyme-linked immunoassays, lcsh:Science, Peptide sequence, chemistry.chemical_classification, 0303 health sciences, Multidisciplinary, Hemoproteins, biology, Molecular Structure, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], Hydrogen bond, Chemistry, Chemical Reactions, Amino acid, Enzymes, Antibodies, Anti-Idiotypic, Hematoporphyrins, Peroxidases, Hapten, Peroxidase, Research Article, Protein Structure, Porphyrins, Stereochemistry, Iron, Biophysics, 010402 general chemistry, Inorganic Chemistry, 03 medical and health sciences, Residue (chemistry), Chemical Biology, Animals, Amino Acid Sequence, Biology, Imidazole, 030304 developmental biology, Binding Sites, Cofactors, Crystal structure, Organic Chemistry, lcsh:R, Proteins, Hydrogen Bonding, Porphyrin, 0104 chemical sciences, biology.protein, Biocatalysis, lcsh:Q, Cofactors (biochemistry), Binding Sites, Antibody, Haptens
Abstract: International audience; We report the crystal structures at 2.05 and 2.45 Å resolution of two antibodies, 13G10 and 14H7, directed against an iron(III)-aaab-carboxyphenylporphyrin, which display some peroxidase activity. Although these two antibodies differ by only one amino acid in their variable l-light chain and display 86% sequence identity in their variable heavy chain, their complementary determining regions (CDR) CDRH1 and CDRH3 adopt very different conformations. The presence of Met or Leu residues at positions preceding residue H101 in CDRH3 in 13G10 and 14H7, respectively, yields to shallow combining sites pockets with different shapes that are mainly hydrophobic. The hapten and other carboxyphenyl-derivatized iron(III)porphyrins have been modeled in the active sites of both antibodies using protein ligand docking with the program GOLD. The hapten is maintained in the antibody pockets of 13G10 and 14H7 by a strong network of hydrogen bonds with two or three carboxylates of the carboxyphenyl substituents of the porphyrin, respectively, as well as numerous stacking and van der Waals interactions with the very hydrophobic CDRH3. However, no amino acid residue was found to chelate the iron. Modeling also allows us to rationalize the recognition of alternative porphyrinic cofactors by the 13G10 and 14H7 antibodies and the effect of imidazole binding on the peroxidase activity of the 13G10/porphyrin complexes.
Published: 2021
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38. Artificial maturation of [FeFe] hydrogenase in a redox polymer film

Author: Christophe Léger, Cecilia Papini, Christina Felbek, Nicolas Plumeré, Marc Fontecave, Steffen Hardt, Debajyoti Pramanik, Vincent Fourmond, Vincent Artero, Bioénergétique et Ingénierie des Protéines (BIP ), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Center of Smart Interfaces, Technische Universität Darmstadt - Technical University of Darmstadt (TU Darmstadt), Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Solar fuels, hydrogen and catalysis (SolHyCat), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM), ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), and Technische Universität Darmstadt (TU Darmstadt)
Subjects: Iron-Sulfur Proteins, Hydrogenase, Scale (ratio), Polymers, 010402 general chemistry, Photochemistry, Electrochemistry, 01 natural sciences, Redox, Catalysis, Electron transfer, Materials Chemistry, chemistry.chemical_classification, biology, 010405 organic chemistry, Metals and Alloys, Active site, food and beverages, Membranes, Artificial, General Chemistry, Polymer, [CHIM.CATA]Chemical Sciences/Catalysis, Enzymes, Immobilized, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, [CHIM.POLY]Chemical Sciences/Polymers, chemistry, Ceramics and Composites, biology.protein
Abstract: International audience; We demonstrate that the insertion of the dinuclear active site of [FeFe] hydrogenase into the apo-enzyme can occur when the enzyme is embedded in a film of redox polymer, under conditions of mediated electron transfer. The maturation can be monitored by electrochemistry, and is as fast as under conditions of direct electron transfer. This new approach clears further the way to the implementation of hydrogenases in large scale real life processes.
Published: 2021
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39. An enzymatic activation of formaldehyde for nucleotide methylation

Author: Bruce A. Palfey, Charles Bou-Nader, Antoine Royant, Ludovic Pecqueur, Philippe Simon, Vincent Guérineau, Frederick Stull, Djemel Hamdane, Murielle Lombard, Marc Fontecave, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), University of Michigan Medical School [Ann Arbor], University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Institut de Chimie des Substances Naturelles (ICSN), Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut de biologie structurale (IBS - UMR 5075), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), European Synchrotron Radiation Facility (ESRF), and ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017)
Subjects: 0301 basic medicine, Stereochemistry, Science, Static Electricity, General Physics and Astronomy, Flavin group, 010402 general chemistry, Methylation, 01 natural sciences, Thymidylate synthase, Article, General Biochemistry, Genetics and Molecular Biology, Cofactor, 03 medical and health sciences, chemistry.chemical_compound, Catalytic Domain, Flavins, Formaldehyde, Thermotoga maritima, Nucleotide, Carbon-13 Magnetic Resonance Spectroscopy, Methylene, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], Purine metabolism, X-ray crystallography, chemistry.chemical_classification, Multidisciplinary, biology, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], Nucleotides, Active site, Thymidylate Synthase, General Chemistry, 0104 chemical sciences, Enzyme Activation, 030104 developmental biology, Enzyme, chemistry, Enzyme mechanisms, Biocatalysis, biology.protein
Abstract: Folate enzyme cofactors and their derivatives have the unique ability to provide a single carbon unit at different oxidation levels for the de novo synthesis of amino-acids, purines, or thymidylate, an essential DNA nucleotide. How these cofactors mediate methylene transfer is not fully settled yet, particularly with regard to how the methylene is transferred to the methylene acceptor. Here, we uncovered that the bacterial thymidylate synthase ThyX, which relies on both folate and flavin for activity, can also use a formaldehyde-shunt to directly synthesize thymidylate. Combining biochemical, spectroscopic and anaerobic crystallographic analyses, we showed that formaldehyde reacts with the reduced flavin coenzyme to form a carbinolamine intermediate used by ThyX for dUMP methylation. The crystallographic structure of this intermediate reveals how ThyX activates formaldehyde and uses it, with the assistance of active site residues, to methylate dUMP. Our results reveal that carbinolamine species promote methylene transfer and suggest that the use of a CH2O-shunt may be relevant in several other important folate-dependent reactions., The bacterial thymidylate synthase ThyX catalyzes the reductive methylation of deoxyuridylate (dUMP) into deoxythymidylate (dTMP) and requires both folate and flavin for activity. Here, the authors combine biochemical experiments, spectroscopic measurements and flavin synthesis chemistry to show that formaldehyde (CH2O) can replace the natural methylene donor of ThyX in a CH2O-shunt reaction, yielding a carbinolamine intermediate with the reduced flavin coenzyme, and they present the crystal structure of this intermediate.
Published: 2021
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40. Heterogenisation of polyoxometalates and other metal-based complexes in metal–organic frameworks: from synthesis to characterisation and applications in catalysis

Author: Olivier Oms, Caroline Mellot-Draznieks, Y. Benseghir, M. Duguet, Anne Dolbecq, Pierre Mialane, P. Gairola, Institut Lavoisier de Versailles (ILV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and ANR-11-LABX-0039,CHARMMMAT,CHimie des ARchitectures MoléculairesMultifonctionnelles et des MATériaux(2011)
Subjects: Materials science, Nanotechnology, 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Electrocatalyst, 01 natural sciences, Redox, 0104 chemical sciences, Catalysis, Metal, Homogeneous, visual_art, visual_art.visual_art_medium, [CHIM]Chemical Sciences, Metal-organic framework, 0210 nano-technology, Selectivity
Abstract: International audience; These last years have seen a huge growing interest in the heterogenisation of molecular catalysts since it allows combining the advantages of homogeneous and heterogeneous catalysis. Besides bringing recyclability, the immobilisation of the catalyst may increase its stability while allowing tuning its selectivity. In this respect, Metal-Organic Frameworks (MOFs) attract an evergrowing interest as a platform for their confinement within their pores or channels. In this review, Cat@MOF composites whereby molecular catalysts (Cats) are immobilised in MOFs through non-covalent interactions with their host, are reviewed thoroughly. Polyoxometalates (POMs) and other metal-based complexes as immobilised molecular species are covered. In the first part, the different synthetic methods and analytical tools are described. A critical analysis of the various physico-chemical methods available to characterise the Cat@MOF composites is provided-a particular attention being paid toward their pertinence for the investigation of the content, the position and the stability of the catalyst within the MOF. Besides, focus is made on non-conventional techniques such as Pair Distribution Function (PDF) and a section is dedicated to the contribution of DFT calculations. In the second part, the applications of these materials in the fields of catalysis, including oxidation and reduction reactions, acid-base catalysis, photo-and electrocatalysis are detailed.
Published: 2021
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41. Structure-based mechanistic insights into catalysis by tRNA thiolation enzymes

Author: Simon Arragain, Ornella Bimai, Béatrice Golinelli-Pimpaneau, Laboratoire de Chimie des Processus Biologiques (LCPB), and Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: chemistry.chemical_element, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, Catalysis, 03 medical and health sciences, 0302 clinical medicine, RNA, Transfer, Structural Biology, Protein biosynthesis, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, RNA, Messenger, RNA Processing, Post-Transcriptional, Molecular Biology, 030304 developmental biology, chemistry.chemical_classification, 0303 health sciences, Messenger RNA, Bacteria, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], RNA, Translation (biology), [CHIM.CATA]Chemical Sciences/Catalysis, Genetic code, Archaea, Sulfur, Oxygen, Enzyme, chemistry, Biochemistry, Biocatalysis, 030217 neurology & neurosurgery
Abstract: International audience; In all domains of life, ribonucleic acid (RNA) maturation includes post-transcriptional chemical modifications of nucleosides. Many sulfur-containing nucleosides have been identified in transfer RNAs (tRNAs), such as the derivatives of 2-thiouridine (s 2 U), 4-thiouridine (s 4 U), 2-thiocytidine (s 2 C), 2-methylthioadenosine (ms 2 A). These modifications are essential for accurate and efficient translation of the genetic code from messenger RNA (mRNA) for protein synthesis. This review summarizes the recent discoveries concerning the mechanistic and structural characterization of tRNA thiolation enzymes that catalyze the non-redox substitution of oxygen for sulfur in nucleosides. Two mechanisms have been described. One involves persulfide formation on catalytic cysteines, while the other uses a [4Fe-4S] cluster, chelated by three conserved cysteines only, as a sulfur carrier. 2
Published: 2020
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42. Effect of Ligands on HP-Induced Unfolding and Oligomerization of β-Lactoglobulin

Author: Burkhard Annighöfer, Camille Loupiac, Simeon Minić, Gaston Hui Bon Hoa, Sophie Combet, Annie Brûlet, Djemel Hamdane, Arnaud Hélary, Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM), Physico-Chimie de l'Aliment et du Vin (PCAV), Procédés Alimentaires et Microbiologiques [Dijon] (PAM), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), LLB - Matière molle et biophysique (MMB), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Université Bourgogne Franche-Comté [COMUE] (UBFC)
Subjects: Whey protein, Protein Folding, [SDV]Life Sciences [q-bio], Biophysics, Ab initio, Lactoglobulins, 010402 general chemistry, Ligands, 01 natural sciences, 03 medical and health sciences, 0404 agricultural biotechnology, Animals, Denaturation (biochemistry), [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Binding site, 030304 developmental biology, 0303 health sciences, Binding Sites, Chemistry, 04 agricultural and veterinary sciences, Articles, Ligand (biochemistry), 040401 food science, 0104 chemical sciences, Covalent bond, Unfolded protein response, Protein folding, Cattle, Hydrophobic and Hydrophilic Interactions
Abstract: To probe intermediate states during unfolding and oligomerization of proteins remains a major challenge. High pressure (HP) is a powerful tool for studying these problems, revealing subtle structural changes in proteins not accessible by other means of denaturation. Bovine β-lactoglobulin (BLG), the main whey protein, has a strong propensity to bind various bioactive molecules, such as retinol and resveratrol, two ligands with different affinity and binding sites. By combining in situ HP-small-angle neutron scattering (SANS) and HP-UV/visible absorption spectroscopy, we report the specific effects of these ligands on 3D conformational and local changes in BLG induced by HP. Depending on BLG concentration, two different unfolding mechanisms are observed in situ under pressures up to ~300 MPa, mediated by the formation of disulfide bonds: either a complete protein unfolding, from native dimers to Gaussian chains, or a partial unfolding with oligomerization in tetramers. Retinol, which has a high affinity for BLG hydrophobic cavity, significantly stabilizes BLG both in 3D and local environments, by shifting the onset of protein unfolding by ~100 MPa. Increasing temperature from 30 to 37°C enhances the hydrophobic stabilization effects of retinol. In contrast, resveratrol, which has a low binding affinity for site(s) on the surface of the BLG, does not induce any significant effect on the structural changes of BLG due to pressure. HP treatment back and forth up to ~300 MPa causes irreversible covalent oligomerization of BLG. Ab initio modeling of SANS shows that the oligomers formed from BLG/retinol complex are smaller and more elongated compared to BLG without ligand or in the presence of resveratrol. By combining HP-SANS and HP-UV/vis absorption spectroscopy, our strategy highlights the crucial role of BLG hydrophobic cavity and opens up new possibilities for the structural determination of HP-induced protein folding intermediates and irreversible oligomerization.STATEMENT OF SIGNIFICANCEHigh pressure (HP) is a powerful probe to access the intermediate states of proteins through subtle structural changes not accessible by other means of denaturation. Bovine β-lactoglobulin (BLG), the main whey protein, is able to bind various bioactive molecules, such as retinol and resveratrol, exhibiting different affinity and binding sites. By combining HP-small-angle neutron scattering and HP-UV/visible absorption spectroscopy, we highlight two different mechanisms during the unfolding and oligomerization of BLG depending on protein concentration. Above all, we show that retinol significantly prevents the unfolding and oligomerization of BLG, unlike resveratrol, emphasizing the crucial role of the hydrophobic cavity in BLG stabilization. Our strategy opens up new possibilities for the structural determination of protein intermediates and oligomers using HP.
Published: 2020
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43. Functionalization of Carbon Nanotubes with Nickel Cyclam for the Electrochemical Reduction of CO 2

Author: Domenico Grammatico, Ngoc Tran Huan, Bao-Lian Su, Yun Li, Silvia Pugliese, Marc Fontecave, Sandrine Zanna, Jérémy Forté, Chaire Chimie des processus biologiques, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université de Namur [Namur] (UNamur), Institut Parisien de Chimie Moléculaire (IPCM), Chimie Moléculaire de Paris Centre (FR 2769), Institut de Chimie du CNRS (INC)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux (IPREM), Université de Pau et des Pays de l'Adour (UPPA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche de Chimie Paris (IRCP), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ministère de la Culture (MC)
Subjects: General Chemical Engineering, 02 engineering and technology, Carbon nanotube, 010402 general chemistry, Electrocatalyst, Electrochemistry, 01 natural sciences, law.invention, chemistry.chemical_compound, law, Cyclam, [CHIM]Chemical Sciences, electrocatalysis, Environmental Chemistry, Moiety, General Materials Science, CO conversion, heterogenization, Electrolysis, carbon nanotubes, Gas diffusion electrode, nickel Cyclam, CO2 conversion, 021001 nanoscience & nanotechnology, 0104 chemical sciences, General Energy, chemistry, Chemical engineering, Electrode, 0210 nano-technology
Abstract: The exploitation of molecular catalysts for CO2 electrolysis requires their immobilization on the cathode of the electrolyzer. As an illustration of this approach, a Ni-cyclam complex with a cyclam derivative functionalized with a pyrene moiety is synthesized, found to be a selective catalyst for CO2 electroreduction to CO, and immobilized on a carbon nanotube-coated gas diffusion electrode by using a noncovalent binding strategy. The as-prepared electrode is efficient, selective, and robust for electrocatalytic reduction of CO2 to CO. Very high turnover numbers (ca. 61460) and turnover frequencies (ca. 4.27 s−1) are enabled by the novel electrode material in organic solvent-water mixtures saturated with CO2. This material provides an interesting platform for further improvement.
Published: 2020
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44. Immobilization of a molecular Re complex on MOF‐derived hierarchical porous carbon for CO2 electroreduction in water/ionic liquid electrolyte

Author: Huan Ngoc Tran, Yun Li, Laurent Billon, Bao-Lian Su, Silvia Pugliese, Marc Fontecave, Domenico Grammatico, Chaire Chimie des processus biologiques, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université de Namur [Namur] (UNamur), Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux (IPREM), and Université de Pau et des Pays de l'Adour (UPPA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Tetrafluoroborate, General Chemical Engineering, CO2 electroreduction, chemistry.chemical_element, 02 engineering and technology, Electrolyte, Ionic liquid, 010402 general chemistry, CO electroreduction, 01 natural sciences, Catalysis, chemistry.chemical_compound, Bipyridine, hierarchical porous carbon, Environmental Chemistry, [CHIM]Chemical Sciences, General Materials Science, heterogenization, catalysis, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, General Energy, [CHIM.POLY]Chemical Sciences/Polymers, chemistry, Chemical engineering, 0210 nano-technology, Hybrid material, Carbon, rhenium complex, Carbon monoxide
Abstract: The development of molecular catalysts for CO 2 electroreduction within electrolyzers requests their immobilization on the electrodes. While a variety of methods have been explored for the heterogenization of homogeneous complexes, a novel approach using a hierarchical porous carbon material, derived from a metal-organic framework, is reported as a support for the well-known molecular catalyst [Re(bpy)(CO) 3 Cl] (bpy=2,2'-bipyridine). This cathodic hybrid material, named Re@HPC (HPC=hierarchical porous carbon), has been tested for CO 2 electroreduction using a mixture of an ionic liquid (1-ethyl-3-methylimidazolium tetrafluoroborate, EMIM) and water as the electrolyte. Interestingly, it catalyzes the conversion of CO 2 into a mixture of carbon monoxide and formic acid, with a selectivity that depends on the applied potential. The present study thus reveals that Re@HPC is a remarkable catalyst, enjoying excellent activity (turnover numbers for CO 2 reduction of 7835 after 2 h at -1.95 V vs. Fc/Fc + with a current density of 6 mA cm -2 ) and good stability. These results emphasize the advantages of integrating molecular catalysts onto such porous carbon materials for developing novel, stable and efficient, catalysts for CO 2 reduction.
Published: 2020
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45. Structure-directing role of immobilized polyoxometalates in the synthesis of porphyrinic Zr-based metal–organic frameworks

Author: Anne Dolbecq, Caroline Mellot-Draznieks, Marc Fontecave, Catherine Roch-Marchal, Mathis Duguet, Mohamed Haouas, Alex Lemarchand, Capucine Sassoye, Youven Benseghir, Pierre Mialane, Maria Gómez-Mingot, Chaire Chimie des processus biologiques, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut Lavoisier de Versailles (ILV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), and Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, 010405 organic chemistry, Metals and Alloys, Structural integrity, General Chemistry, 010402 general chemistry, 01 natural sciences, Catalysis, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Chemical engineering, Polyoxometalate, Materials Chemistry, Ceramics and Composites, [CHIM]Chemical Sciences, Metal-organic framework, Topology (chemistry)
Abstract: International audience; We evidence the structure-directing role of the PW12O403-polyoxometalate in the synthesis of porphyrinicMOFswhereby it promotes the formation of the kinetic topology. Its immobilization into the MOF is successfully achieved at high temperature yielding the kinetic MOF-525/PCN-224 phases, while prohibiting the formation of the thermodynamic MOF-545 product. A combined experimental and theoretical approach uses differential PDF and DFT calculations along with solid-state NMRto show the structural integrity of the hosted POM andits location in the vicinity of the Zr-based nodes.
Published: 2020
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46. Dopage (Co/Fe) de nanoparticules de RuO2 : synthèse, modélisation et caractérisation structurale

Author: Ellezam, Laura, Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, Clément Sanchez, and Caroline Mellot-Draznieks
Subjects: Calculs DFT, Paire of Distribution Function, Dopage, Description à l’échelle atomique, RuO2, Doping, Nanoparticules, Nanoparticles, DFT calculation, [CHIM.CATA]Chemical Sciences/Catalysis, Atomic scale description, Fonction de Distribution de Paire atomique (PDF)
Abstract: The aim of this work is the full analysis of RuO2 nanoparticles (NPs) doped with Co or Fe. This is a big challenge because of the size of these systems (1.0 - 2.5 nm). Synthesis were conducted by three different aqueous pathways at low temperature: via sol-gel, hydrothermal and by co-precipitation methods. Fe atoms replaces easily Ru, whereas it is more difficult for Co. Several parameters had to be changed to obtain a successful doping. In order to characterize the local structure of Co or Fe-doped RuO2 nanoparticles, and understand the structural modifications, a coupling between modelling with DFT calculation and analysis by Pair Distribution Function (PDF) was set up. First a bulk model and after a NP model was built and optimized by DFT. It was seen that numerous doping atoms tend to be localized at the surface of the NPs whereas it is more thermodynamically stable to have a good dispersion when the number of doping atom is smaller. From these DFT model, PDF curves were calculated and compared with experimental PDF curves. These comparisons allow to identify the rutile structure, describe the local structure, and to validate DFT models. It also allows the attribution of distances in the structure and shows the need to consider specifically the surface modifications. This PDF/DFT conclusions were validated by high level STEM-HAADF-EELS analysis.; Ce travail concerne l’analyse complète des nanoparticules (NPs) de RuO2 dopées au Co ou au Fe. Le défi ici réside dans la taille des systèmes, comprise entre 1 et 2,5nm. Les synthèses sont réalisées par trois voies différentes de chimie douce en solvant aqueux : la voie sol-gel, hydrothermale, et co-précipitation. Le Fe se substitue facilement au Ru, le Co plus difficilement. À l’issue de l’étude de ces méthodes de synthèse, des NPs dopées au Co et au Fe ont été synthétisées. Afin de les caractériser et de comprendre l’influence, notamment structurale, des dopants, les calculs DFT et la caractérisation par l’étude de la fonction de distribution de paires atomiques (PDF) ont été couplés. La construction de modèle bulk puis des modèles de NPs ont été construits et optimisés. Les études de localisation des dopants montrent qu’ils se concentrent préférentiellement en surface, éloignés par des atomes de Ru dans le cas d’un nombre très faible d’atome. En augmentant le nombre d’atomes dopants, une étude préliminaire suggère un regroupement de surface des atomes dopants. À partir de ces modèles, des PDFs sont calculées et comparées aux PDFs expérimentales des NPs synthétisées. Ainsi il est possible d’attribuer en détail les PDFs expérimentales et de décrire l’arrangement local des NPs dopées ainsi que de valider les modèles DFT. Il a donc été mis en place un protocole de caractérisation permettant de décrire l’arrangement locale et de démontrer le dopage, dans des NPs de moins de 5 nm en utilisant la DFT et l’analyse PDF, avec confirmation par des analyses STEM-HAADF-EELS.
Published: 2020

47. A bioinspired molybdenum-copper molecular catalyst for CO 2 electroreduction

Author: Tanya K. Todorova, Marc Fontecave, Subal Dey, Ahmed Mouchfiq, Victor Mougel, Chaire Chimie des processus biologiques, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Department of Chemistry and Applied Biosciences [ETH Zürich] (D-CHAB), and Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)
Subjects: biology, 010405 organic chemistry, Chemistry, Hydride, Active site, Protonation, General Chemistry, 010402 general chemistry, 01 natural sciences, 0104 chemical sciences, 3. Good health, Catalysis, chemistry.chemical_compound, 13. Climate action, Polymer chemistry, biology.protein, Moiety, [CHIM]Chemical Sciences, Formate, Bimetallic strip, Carbon monoxide dehydrogenase
Abstract: International audience; Non-noble metal molecular catalysts mediating the electrocatalytic reduction of carbon dioxide are still scarce. This work reports the electrochemical reduction of CO 2 to formate catalyzed by the bimetallic complex [(bdt)Mo VI (O)S 2 Cu I CN] 2À (bdt ¼ benzenedithiolate), a mimic of the active site of the Mo-Cu carbon monoxide dehydrogenase enzyme (CODH2). Infrared spectroelectrochemical (IR-SEC) studies coupled with density functional theory (DFT) computations revealed that the complex is only a pre-catalyst, the active catalyst being generated upon reduction in the presence of CO 2. We found that the two-electron reduction of [(bdt)Mo VI (O)S 2 Cu I CN] 2À triggers the transfer of the oxo moiety to CO 2 forming CO 3 2À and the complex [(bdt)Mo IV S 2 Cu I CN] 2À and that a further one-electron reduction is needed to generate the active catalyst. Its protonation yields a reactive Mo V H hydride intermediate which reacts with CO 2 to produce formate. These findings are particularly relevant to the design of catalysts from metal oxo precursors.
Published: 2020
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48. Co-immobilization of a Rh Catalyst and a Keggin Polyoxometalate in the UiO-67 Zr-Based Metal–Organic Framework: In Depth Structural Characterization and Photocatalytic Properties for CO2 Reduction

Author: Pierre Mialane, Alex Lemarchand, Anne Dolbecq, Capucine Sassoye, Catherine Roch-Marchal, Caroline Mellot-Draznieks, Minh-Huong Ha-Thi, Thomas Pino, Mathis Duguet, Mohamed Haouas, Marc Fontecave, Youven Benseghir, Maria Gómez-Mingot, Chaire Chimie des processus biologiques, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), IRCER - Axe 3 : organisation structurale multiéchelle des matériaux (IRCER-AXE3), Institut de Recherche sur les CERamiques (IRCER), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut Lavoisier de Versailles (ILV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Moléculaires d'Orsay (ISMO), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Photophysique et Photochimie Supramoléculaires et Macromoléculaires (PPSM), Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Ecole Normale Supérieure Paris-Saclay (ENS Paris Saclay), Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), and Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Catalytic complex, Chemistry, Inorganic chemistry, Co immobilization, General Chemistry, 010402 general chemistry, 01 natural sciences, Biochemistry, Catalysis, 0104 chemical sciences, Metal, Colloid and Surface Chemistry, visual_art, Polyoxometalate, visual_art.visual_art_medium, Photocatalysis, [CHIM]Chemical Sciences, Metal-organic framework
Abstract: International audience; The Keggin-type polyoxometalate (POM) PW12O403– and the catalytic complex Cp*Rh(bpydc)Cl2 (bpydc = 2,2′-bipyridine-5,5′-dicarboxylic acid) were coimmobilized in the Zr(IV) based metal organic framework UiO-67. The POM is encapsulated within the cavities of the MOF by in situ synthesis, and then, the Rh catalytic complex is introduced by postsynthetic linker exchange. Infrared and Raman spectroscopies, 31P and 13C MAS NMR, N2 adsorption isotherms, and X-ray diffraction indicate the structural integrity of all components (POM, Rh-complex and MOF) within the composite of interest (PW12,Cp*Rh)@UiO-67. DFT calculations identified two possible locations of the POM in the octahedral cavities of the MOF: one at the center of a UiO-67 pore with the Cp*Rh complex pointing toward an empty pore and one off-centered with the Cp*Rh pointing toward the POM. 31P–1H heteronuclear (HETCOR) experiments ascertained the two environments of the POM, equally distributed, with the POM in interaction either with the Cp* fragment or with the organic linker. In addition, Pair Distribution Function (PDF) data were collected on the POM@MOF composite and provided key evidence of the structural integrity of the POM once immobilized into the MOF. The photocatalytic activity of the (PW12,Cp*Rh)@UiO-67 composite for CO2 reduction into formate and hydrogen were evaluated. The formate production was doubled when compared with that observed with the POM-free Cp*Rh@UiO-67 catalyst and reached TONs as high as 175 when prepared as thin films, showing the beneficial influence of the POM. Finally, the stability of the composite was assessed by means of recyclability tests. The combination of XRD, IR, ICP, and PDF experiments was essential in confirming the integrity of the POM, the catalyst, and the MOF after catalysis.
Published: 2020
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49. High-Current-Density CO2-to-CO Electroreduction on Ag-Alloyed Zn Dendrites at Elevated Pressure

Author: Dario Taverna, Sarah Lamaison, Philippe Marcus, Juliette Blanchard, David W. Wakerley, Domitille Giaume, Marc Fontecave, Victor Mougel, David Montero, Dimitri Mercier, Gwenaëlle Rousse, Chaire Chimie des processus biologiques, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Réactivité de Surface (LRS), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), EA4278 Laboratoire de Pharm-Ecologie Cardiovasculaire (LaPEC), Avignon Université (AU), Chimie du solide et de l'énergie (CSE), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche de Chimie Paris (IRCP), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ministère de la Culture (MC), Ecole Nationale Supérieure de Chimie de Paris (Chimie ParisTech), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Chimie ParisTech, Laboratoire de Chimie Inorganique et Biologique, Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU), Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Ministère de la Culture (MC)
Subjects: Materials science, 02 engineering and technology, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Electrocatalyst, 7. Clean energy, 01 natural sciences, 0104 chemical sciences, Artificial photosynthesis, chemistry.chemical_compound, General Energy, Chemical engineering, chemistry, Electrode, [CHIM]Chemical Sciences, 0210 nano-technology, Selectivity, Porosity, Partial current, Carbon monoxide, Bar (unit)
Abstract: Summary The electrocatalytic conversion of CO2 into valuable chemical feedstocks is a highly sought-after route to recycle CO2 emissions. Among the expected products, CO is a valuable synthon for organic syntheses and fuel generation. Nevertheless, most current electrocatalytic systems do not generate CO at a sufficient rate or purity for its subsequent direct conversion. Herein, we report the rational design of novel and highly active Ag-alloyed Zn dendritic electrodes with remarkable CO2-to-CO selectivity. Through fine-tuning of the individual electrodeposition parameters, the Ag content, porosity, thickness, and surface area of the electrodes were optimized, leading to a CO2-to-CO selectivity as high as 91%, which could be sustained above an average of 90% over 40 h. Increase of the CO2 pressure (up to 9.5 bar) to enhance the CO2 concentration allowed CO partial current densities as high as –286 mA.cm−2 to be achieved, setting a new record for predominantly Zn-based electrodes operating in neutral pH.
Published: 2020
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50. Synthetic and computational assessment of a chiral metal-organic framework catalyst for predictive asymmetric transformation

Author: Jonathan Bonnefoy, Tanya K. Todorova, Caroline Mellot-Draznieks, Alexandre Legrand, Elsje Alessandra Quadrelli, Elise Bernoud, Jérôme Canivet, IRCELYON-Ingéniérie, du matériau au réacteur (ING), Institut de recherches sur la catalyse et l'environnement de Lyon (IRCELYON), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie des Processus Biologiques (LCPB), and Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: inorganic chemicals, Materials science, 010405 organic chemistry, organic chemicals, General Chemistry, [CHIM.CATA]Chemical Sciences/Catalysis, 010402 general chemistry, Transfer hydrogenation, Heterogeneous catalysis, 01 natural sciences, Combinatorial chemistry, [SDE.ES]Environmental Sciences/Environmental and Society, 0104 chemical sciences, Catalysis, chemistry.chemical_compound, Chemistry, Molecular recognition, chemistry, Metal-organic framework, heterocyclic compounds, Enantiomer, Enantiomeric excess, Acetophenone
Abstract: Understanding and controlling molecular recognition mechanisms at a chiral solid interface is a continuously addressed challenge in heterogeneous catalysis. Here, the molecular recognition of a chiral peptide-functionalized metal–organic framework (MOF) catalyst towards a pro-chiral substrate is evaluated experimentally and in silico. The MIL-101 metal–organic framework is used as a macroligand for hosting a Noyori-type chiral ruthenium molecular catalyst, namely (benzene)Ru@MIL-101-NH-Gly-Pro. Its catalytic perfomance toward the asymmetric transfer hydrogenation (ATH) of acetophenone into R- and S-phenylethanol are assessed. The excellent match between the experimentally obtained enantiomeric excesses and the computational outcomes provides a robust atomic-level rationale for the observed product selectivities. The unprecedented role of the MOF in confining the molecular Ru-catalyst and in determining the access of the prochiral substrate to the active site is revealed in terms of highly face-specific host–guest interactions. The predicted surface-specific face differentiation of the prochiral substrate is experimentally corroborated since a three-fold increase in enantiomeric excess is obtained with the heterogeneous MOF-based catalyst when compared to its homogeneous molecular counterpart., Understanding and controlling molecular recognition mechanisms at a chiral solid interface has been addressed in metal–organic framework catalysts for the asymmetric transfer hydrogenation reaction.
Published: 2020
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