Author: "Sébastien Fort" - Searchworks@Jio Institute Digital Library Search Results

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115 results on '"Sébastien Fort"'

1. The evolutionary advantage of an aromatic clamp in plant family 3 glycoside exo-hydrolases

Author: Sukanya Luang, Xavier Fernández-Luengo, Alba Nin-Hill, Victor A. Streltsov, Julian G. Schwerdt, Santiago Alonso-Gil, James R. Ketudat Cairns, Stéphanie Pradeau, Sébastien Fort, Jean-Didier Maréchal, Laura Masgrau, Carme Rovira, and Maria Hrmova
Subjects: Science
Abstract: Barley β-d-glucan glucohydrolase is a glycoside hydrolase family 3 (GH3) enzyme critical for growth and development. Here the authors carryout mutagenesis, structural analyses and multi-scale molecular dynamics to examine the binding and conformational behaviour of several β-d-glucosides during the substrate-product assisted catalysis that operates in GH3 hydrolases.
Published: 2022
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2. Lipo-Chitooligosaccharides Induce Specialized Fungal Metabolite Profiles That Modulate Bacterial Growth

Author: Tomás A. Rush, Joanna Tannous, Matthew J. Lane, Muralikrishnan Gopalakrishnan Meena, Alyssa A. Carrell, Jacob J. Golan, Milton T. Drott, Sylvain Cottaz, Sébastien Fort, Jean-Michel Ané, Nancy P. Keller, Dale A. Pelletier, Daniel A. Jacobson, David Kainer, Paul E. Abraham, Richard J. Giannone, and Jesse L. Labbé
Subjects: lipo-chitooligosaccharides, secondary metabolites, synergism, biosynthetic gene clusters, bacteria, Aspergillus, Microbiology, QR1-502
Abstract: ABSTRACT Lipo-chitooligosaccharides (LCOs) are historically known for their role as microbial-derived signaling molecules that shape plant symbiosis with beneficial rhizobia or mycorrhizal fungi. Recent studies showing that LCOs are widespread across the fungal kingdom have raised questions about the ecological function of these compounds in organisms that do not form symbiotic relationships with plants. To elucidate the ecological function of these compounds, we investigate the metabolomic response of the ubiquitous human pathogen Aspergillus fumigatus to LCOs. Our metabolomics data revealed that exogenous application of various types of LCOs to A. fumigatus resulted in significant shifts in the fungal metabolic profile, with marked changes in the production of specialized metabolites known to mediate ecological interactions. Using network analyses, we identify specific types of LCOs with the most significant effect on the abundance of known metabolites. Extracts of several LCO-induced metabolic profiles significantly impact the growth rates of diverse bacterial species. These findings suggest that LCOs may play an important role in the competitive dynamics of non-plant-symbiotic fungi and bacteria. This study identifies specific metabolomic profiles induced by these ubiquitously produced chemicals and creates a foundation for future studies into the potential roles of LCOs as modulators of interkingdom competition. IMPORTANCE The activation of silent biosynthetic gene clusters (BGC) for the identification and characterization of novel fungal secondary metabolites is a perpetual motion in natural product discoveries. Here, we demonstrated that one of the best-studied symbiosis signaling compounds, lipo-chitooligosaccharides (LCOs), play a role in activating some of these BGCs, resulting in the production of known, putative, and unknown metabolites with biological activities. This collection of metabolites induced by LCOs differentially modulate bacterial growth, while the LCO standards do not convey the same effect. These findings create a paradigm shift showing that LCOs have a more prominent role outside of host recognition of symbiotic microbes. Importantly, our work demonstrates that fungi use LCOs to produce a variety of metabolites with biological activity, which can be a potential source of bio-stimulants, pesticides, or pharmaceuticals.
Published: 2022
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3. Lipo-chitooligosaccharides as regulatory signals of fungal growth and development

Author: Tomás Allen Rush, Virginie Puech-Pagès, Adeline Bascaules, Patricia Jargeat, Fabienne Maillet, Alexandra Haouy, Arthur QuyManh Maës, Cristobal Carrera Carriel, Devanshi Khokhani, Michelle Keller-Pearson, Joanna Tannous, Kevin R. Cope, Kevin Garcia, Junko Maeda, Chad Johnson, Bailey Kleven, Quanita J. Choudhury, Jessy Labbé, Candice Swift, Michelle A. O’Malley, Jin Woo Bok, Sylvain Cottaz, Sébastien Fort, Verena Poinsot, Michael R. Sussman, Corinne Lefort, Jeniel Nett, Nancy P. Keller, Guillaume Bécard, and Jean-Michel Ané
Subjects: Science
Abstract: Lipo-chitooligosaccharides (LCOs) are signaling molecules produced by certain bacteria and fungi that establish symbiotic relationships with plants. Here, the authors show that LCOs are produced also by many other, non-symbiotic fungi, and regulate fungal growth and development.
Published: 2020
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4. Expanding the Biological Role of Lipo-Chitooligosaccharides and Chitooligosaccharides in Laccaria bicolor Growth and Development

Author: Manuel I. Villalobos Solis, Nancy L. Engle, Margaret K. Spangler, Sylvain Cottaz, Sébastien Fort, Junko Maeda, Jean-Michel Ané, Timothy J. Tschaplinski, Jesse L. Labbé, Robert L. Hettich, Paul E. Abraham, and Tomás A. Rush
Subjects: Laccaria bicolor, lipo-chitooligosaccharides, polarized growth, proteomics, chitooligosaccharides, Plant culture, SB1-1110
Abstract: The role of lipo-chitooligosaccharides (LCOs) as signaling molecules that mediate the establishment of symbiotic relationships between fungi and plants is being redefined. New evidence suggests that the production of these molecular signals may be more of a common trait in fungi than what was previously thought. LCOs affect different aspects of growth and development in fungi. For the ectomycorrhizal forming fungi, Laccaria bicolor, the production and effects of LCOs have always been studied with a symbiotic plant partner; however, there is still no scientific evidence describing the effects that these molecules have on this organism. Here, we explored the physiological, molecular, and metabolomic changes in L. bicolor when grown in the presence of exogenous sulfated and non-sulfated LCOs, as well as the chitooligomers, chitotetraose (CO4), and chitooctaose (CO8). Physiological data from 21 days post-induction showed reduced fungal growth in response to CO and LCO treatments compared to solvent controls. The underlying molecular changes were interrogated by proteomics, which revealed substantial alterations to biological processes related to growth and development. Moreover, metabolite data showed that LCOs and COs caused a downregulation of organic acids, sugars, and fatty acids. At the same time, exposure to LCOs resulted in the overproduction of lactic acid in L. bicolor. Altogether, these results suggest that these signals might be fungistatic compounds and contribute to current research efforts investigating the emerging impacts of these molecules on fungal growth and development.
Published: 2022
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5. A combination of chitooligosaccharide and lipochitooligosaccharide recognition promotes arbuscular mycorrhizal associations in Medicago truncatula

Author: Feng Feng, Jongho Sun, Guru V. Radhakrishnan, Tak Lee, Zoltán Bozsóki, Sébastien Fort, Aleksander Gavrin, Kira Gysel, Mikkel B. Thygesen, Kasper Røjkjær Andersen, Simona Radutoiu, Jens Stougaard, and Giles E. D. Oldroyd
Subjects: Science
Abstract: Polysaccharide molecules chitooligosaccharides (COs) and peptidoglycan not only activate plant immunity but also trigger plant symbiosis signalling. Here the authors show that a combination of COs and lipochitooligosaccharides (LCOs) act synergistically to suppress immunity and promote symbiosis to facilitate beneficial fungal associations.
Published: 2019
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6. Anomeric memory of the glycosidic bond upon fragmentation and its consequences for carbohydrate sequencing

Author: Baptiste Schindler, Loïc Barnes, Gina Renois, Christopher Gray, Stéphane Chambert, Sébastien Fort, Sabine Flitsch, Claire Loison, Abdul-Rahman Allouche, and Isabelle Compagnon
Subjects: Science
Abstract: Establishing generic carbohydrate sequencing methods is both a major scientific challenge and a strategic priority. Here the authors show a hybrid analytical approach integrating molecular spectroscopy and mass spectrometry to resolve carbohydrate isomerism, anomeric configuration, regiochemistry and stereochemistry.
Published: 2017
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7. Optimizing Chitin Depolymerization by Lysozyme to Long-Chain Oligosaccharides

Author: Arnaud Masselin, Antoine Rousseau, Stéphanie Pradeau, Laure Fort, Rodolphe Gueret, Laurine Buon, Sylvie Armand, Sylvain Cottaz, Luc Choisnard, and Sébastien Fort
Subjects: chitin oligosaccharides, chemo-enzymatic synthesis, lysozyme, response surface methodology, Biology (General), QH301-705.5
Abstract: Chitin oligosaccharides (COs) hold high promise as organic fertilizers in the ongoing agro-ecological transition. Short- and long-chain COs can contribute to the establishment of symbiotic associations between plants and microorganisms, facilitating the uptake of soil nutrients by host plants. Long-chain COs trigger plant innate immunity. A fine investigation of these different signaling pathways requires improving the access to high-purity COs. Here, we used the response surface methodology to optimize the production of COs by enzymatic hydrolysis of water-soluble chitin (WSC) with hen egg-white lysozyme. The influence of WSC concentration, its acetylation degree, and the reaction time course were modelled using a Box–Behnken design. Under optimized conditions, water-soluble COs up to the nonasaccharide were formed in 51% yield and purified to homogeneity. This straightforward approach opens new avenues to determine the complex roles of COs in plants.
Published: 2021
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8. Mycorrhizal lipochitinoligosaccharides (LCOs) depolarize root hairs of Medicago truncatula.

Author: Anna-Lena Hürter, Sébastien Fort, Sylvain Cottaz, Rainer Hedrich, Dietmar Geiger, and M Rob G Roelfsema
Subjects: Medicine, Science
Abstract: Arbuscular Mycorrhiza and Root Nodule Symbiosis are symbiotic interactions with a high benefit for plant growth and crop production. Thus, it is of great interest to understand the developmental process of these symbioses in detail. We analysed very early symbiotic responses of Medicago truncatula root hair cells, by stimulation with lipochitinoligosaccharides specific for the induction of nodules (Nod-LCOs), or the interaction with mycorrhiza (Myc-LCOs). Intracellular micro electrodes were used, in combination with Ca2+ sensitive reporter dyes, to study the relations between cytosolic Ca2+ signals and membrane potential changes. We found that sulfated Myc- as well as Nod-LCOs initiate a membrane depolarization, which depends on the chemical composition of these signaling molecules, as well as the genotype of the plants that were studied. A successive application of sulfated Myc-LCOs and Nod-LCOs resulted only in a single transient depolarization, indicating that Myc-LCOs can repress plasma membrane responses to Nod-LCOs. In contrast to current models, the Nod-LCO-induced depolarization precedes changes in the cytosolic Ca2+ level of root hair cells. The Nod-LCO induced membrane depolarization thus is most likely independent of cytosolic Ca2+ signals and nuclear Ca2+ spiking.
Published: 2018
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9. Discrimination of Different Foodborne Pathogens onto Carbohydrate Microarrays Using Surface Plasmon Resonance Imaging.

Author: Emilie Bulard, Aurélie Bouchet-Spinelli, Patricia Chaud, André Roget, Roberto Calemczuk, Sébastien Fort, and Thierry Livache
Published: 2015

10. Evolution of lipochitooligosaccharide binding to a LysM-RLK for nodulation in Medicago truncatula

Author: Julie Cullimore, Judith Fliegmann, Virginie Gasciolli, Chrystel Gibelin-Viala, Noémie Carles, Thi-Bich Luu, Ariane Girardin, Marie Cumener, Fabienne Maillet, Stéphanie Pradeau, Sébastien Fort, Jean-Jacques Bono, Clare Gough, and Benoit Lefebvre
Subjects: Physiology, Cell Biology, Plant Science, General Medicine
Abstract: Lysin motif receptor like kinases (LysM-RLKs) are involved in the perception of chitooligosaccharides (COs) and related lipochitooligosaccharides (LCOs) in plants. Expansion and divergence of the gene family during evolution have led to various roles in symbiosis and defence. By studying proteins of the LYR-IA subclass of LysM-RLKs of the Poaceae, we show here that they are high affinity LCO binding proteins with a lower affinity for COs, consistent with a role in LCO perception to establish arbuscular mycorrhiza (AM). In Papilionoid legumes whole genome duplication has resulted in two LYR-IA paralogs, MtLYR1 and MtNFP in Medicago truncatula, with MtNFP playing an essential role in the root nodule symbiosis with nitrogen-fixing rhizobia. We show that MtLYR1 has retained the ancestral LCO binding characteristic and is dispensable for AM. Domain swapping between the three Lysin motifs (LysMs) of MtNFP and MtLYR1 and mutagenesis in MtLYR1 suggest that the MtLYR1 LCO binding site is on the second LysM, and that divergence in MtNFP led to better nodulation, but surprisingly with decreased LCO binding. These results suggest that divergence of the LCO binding site has been important for the evolution of a role of MtNFP in nodulation with rhizobia.
Published: 2023
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11. Hijacking the Peptidoglycan Recycling Pathway of Escherichia coli to Produce Muropeptides

Author: Antoine Rousseau, Julie Michaud, Stéphanie Pradeau, Sylvie Armand, Sylvain Cottaz, Emeline Richard, and Sébastien Fort
Subjects: Organic Chemistry, General Chemistry, Catalysis
Abstract: Soluble fragments of peptidoglycan called muropeptides are released from the cell wall of bacteria as part of their metabolism or as a result of biological stresses. These compounds trigger immune responses in mammals and plants. In bacteria, they play a major role in the induction of antibiotic resistance. The development of efficient methods to produce muropeptides is, therefore, desirable both to address their mechanism of action and to design new antibacterial and immunostimulant agents. Herein, we engineered the peptidoglycan recycling pathway of Escherichia coli to produce N-acetyl-β-D-glucosaminyl-(1→4)-1,6-anhydro-N-acetyl-β-D-muramic acid (GlcNAc-anhMurNAc), a common precursor of Gram-negative and Gram-positive muropeptides. Inactivation of the hexosaminidase nagZ gene allowed the efficient production of this key disaccharide, providing access to Gram-positive muropeptides through subsequent chemical peptide conjugation. E. coli strains deficient in both NagZ hexosaminidase and amidase activities further enabled the in vivo production of Gram-negative muropeptides containing meso-diaminopimelic acid, a rarely available amino acid.
Published: 2022
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12. Distinct genetic basis for root responses to lipo-chitooligosaccharide signal molecules from different microbial origins

Author: Guillaume Bécard, Christophe Jacquet, Olivier André, Virginie Puech-Pagès, Sylvain Cottaz, Emilie Amblard, Fabienne Maillet, Maxime Bonhomme, Magali Garcia, Sébastien Fort, Clare Gough, and Sandra Bensmihen
Subjects: Lipopolysaccharides, 0106 biological sciences, 0301 basic medicine, Root (linguistics), Kingdom Fungi, Physiology, Oligosaccharides, Chitin, Genome-wide association study, Plant Science, 01 natural sciences, Rhizobia, 03 medical and health sciences, Mycorrhizae, Medicago truncatula, Symbiosis, Legume, Genetics, Chitosan, biology, fungi, Heritability, biology.organism_classification, Phenotype, 030104 developmental biology, Genome-Wide Association Study, Signal Transduction, 010606 plant biology & botany
Abstract: Lipo-chitooligosaccharides (LCOs) were originally found as symbiotic signals called Nod Factors (Nod-LCOs) controlling the nodulation of legumes by rhizobia. More recently, LCOs were also found in symbiotic fungi and, more surprisingly, very widely in the kingdom Fungi, including in saprophytic and pathogenic fungi. The LCO-V(C18:1, fucosylated/methyl fucosylated), hereafter called Fung-LCOs, are the LCO structures most commonly found in fungi. This raises the question of how legume plants such as Medicago truncatula can discriminate between Nod-LCOs and Fung-LCOs. To address this question, we performed a genome-wide association study on 173 natural accessions of M. truncatula, using a root branching phenotype and a newly developed local score approach. Both Nod-LCOs and Fung-LCOs stimulated root branching in most accessions, but the root responses to these two types of LCO molecules were not correlated. In addition, the heritability of the root response was higher for Nod-LCOs than for Fung-LCOs. We identified 123 loci for Nod-LCO and 71 for Fung-LCO responses, of which only one was common. This suggests that Nod-LCOs and Fung-LCOs both control root branching but use different molecular mechanisms. The tighter genetic constraint of the root response to Fung-LCOs possibly reflects the ancestral origin of the biological activity of these molecules.
Published: 2021
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13. Lipo-chitooligosaccharides as regulatory signals of fungal growth and development

Author: Candice L. Swift, Arthur QuyManh Maes, Nancy P. Keller, Cristobal Carrera Carriel, Kevin Garcia, Guillaume Bécard, Joanna Tannous, Quanita J. Choudhury, Jean-Michel Ané, Michelle A. O’Malley, Junko Maeda, Jin Woo Bok, Michelle Keller-Pearson, Tomás Allen Rush, Patricia Jargeat, Virginie Puech-Pagès, Sylvain Cottaz, Michael R. Sussman, Fabienne Maillet, Jeniel E. Nett, Adeline Bascaules, Jessy Labbé, Kevin R. Cope, Alexandra Haouy, Bailey Kleven, Véréna Poinsot, Chad J. Johnson, Sébastien Fort, Corinne Lefort, Devanshi Khokhani, Fort, Sébastien, University of Wisconsin-Madison, Oak Ridge National Laboratory [Oak Ridge] (ORNL), UT-Battelle, LLC, Evolution des Interactions Plantes-Microorganismes, Laboratoire de Recherche en Sciences Végétales (LRSV), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Metatoul - Agromix, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-MetaboHUB-MetaToul, Génopole Toulouse Midi-Pyrénées [Auzeville] (GENOTOUL), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole Nationale Vétérinaire de Toulouse (ENVT), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Génopole Toulouse Midi-Pyrénées [Auzeville] (GENOTOUL), Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Ecole Nationale Vétérinaire de Toulouse (ENVT), Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Interactions moléculaires et réactivité chimique et photochimique (IMRCP), Institut de Chimie de Toulouse (ICT-FR 2599), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Evolution et Diversité Biologique (EDB), Laboratoire des Interactions Plantes Microbes Environnement (LIPME), Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), South Dakota State University (SDSTATE), North Carolina State University [Raleigh] (NC State), University of North Carolina System (UNC), The University of Tennessee [Knoxville], University of Georgia [USA], University of California [Santa Barbara] (UC Santa Barbara), University of California (UC), Centre de Recherches sur les Macromolécules Végétales (CERMAV), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Université Fédérale Toulouse Midi-Pyrénées, Interactions Microbiennes dans la Rhizosphère et les Racines, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-MetaToul-MetaboHUB, Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Vétérinaire de Toulouse (ENVT), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, University of California [Santa Barbara] (UCSB), University of California, Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), MetaToul Agromix, Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-MetaboHUB-MetaToul, MetaboHUB-Génopole Toulouse Midi-Pyrénées [Auzeville] (GENOTOUL), Université de Toulouse (UT)-Université de Toulouse (UT)-Ecole Nationale Vétérinaire de Toulouse (ENVT), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-MetaboHUB-Génopole Toulouse Midi-Pyrénées [Auzeville] (GENOTOUL), Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Ecole Nationale Vétérinaire de Toulouse (ENVT), Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Fluides, Energie, Réacteurs, Matériaux et Transferts (FERMAT), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), BIBAC - Chimie analytique et interactions biomolécules - matière molle biomimétique (BIBAC), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT), and ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017)
Subjects: 0301 basic medicine, Hypha, Science, General Physics and Astronomy, Oligosaccharides, Chitin, 02 engineering and technology, Biology, General Biochemistry, Genetics and Molecular Biology, Article, Microbiology, Microbial ecology, 03 medical and health sciences, Fungal biology, Pseudohyphal growth, Symbiosis, Ascomycota, Mycorrhizae, Spore germination, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], Cellular microbiology, Fungal ecology, lcsh:Science, [SDV.BBM.BC] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], [SDV.MP.MYC]Life Sciences [q-bio]/Microbiology and Parasitology/Mycology, Chitosan, Multidisciplinary, Ecology, Phylum, Basidiomycota, Fatty Acids, fungi, Fungi, General Chemistry, Spores, Fungal, 021001 nanoscience & nanotechnology, biology.organism_classification, [SDV.MP.MYC] Life Sciences [q-bio]/Microbiology and Parasitology/Mycology, Spore, 030104 developmental biology, lcsh:Q, 0210 nano-technology, Bacteria, Rhizobium, Signal Transduction
Abstract: Lipo-chitooligosaccharides (LCOs) are signaling molecules produced by rhizobial bacteria that trigger the nodulation process in legumes, and by some fungi that also establish symbiotic relationships with plants, notably the arbuscular and ecto mycorrhizal fungi. Here, we show that many other fungi also produce LCOs. We tested 59 species representing most fungal phyla, and found that 53 species produce LCOs that can be detected by functional assays and/or by mass spectroscopy. LCO treatment affects spore germination, branching of hyphae, pseudohyphal growth, and transcription in non-symbiotic fungi from the Ascomycete and Basidiomycete phyla. Our findings suggest that LCO production is common among fungi, and LCOs may function as signals regulating fungal growth and development., Lipo-chitooligosaccharides (LCOs) are signaling molecules produced by certain bacteria and fungi that establish symbiotic relationships with plants. Here, the authors show that LCOs are produced also by many other, non-symbiotic fungi, and regulate fungal growth and development.
Published: 2020
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14. A combination of chitooligosaccharide and lipochitooligosaccharide recognition promotes arbuscular mycorrhizal associations in Medicago truncatula

Author: Kira Gysel, Feng Feng, Simona Radutoiu, Zoltan Bozsoki, Giles E. D. Oldroyd, Kasper R. Andersen, Mikkel B. Thygesen, Sébastien Fort, Jongho Sun, Guru V. Radhakrishnan, Aleksander Gavrin, Jens Stougaard, Tak Lee, Feng, Feng [0000-0003-1382-305X], Radhakrishnan, Guru V [0000-0003-0381-8804], Lee, Tak [0000-0001-7008-7605], Fort, Sébastien [0000-0002-6133-9900], Gavrin, Aleksander [0000-0003-0179-8491], Gysel, Kira [0000-0003-4245-9998], Thygesen, Mikkel B [0000-0002-0158-2802], Andersen, Kasper Røjkjær [0000-0002-4415-8067], Stougaard, Jens [0000-0002-9312-2685], Oldroyd, Giles ED [0000-0002-5245-6355], Apollo - University of Cambridge Repository, Sainsbury Laboratory Cambridge University (SLCU), University of Cambridge [UK] (CAM), Aarhus University [Aarhus], Centre de Recherches sur les Macromolécules Végétales (CERMAV ), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), University of Copenhagen = Københavns Universitet (KU), and Oldroyd, Giles E D [0000-0002-5245-6355]
Subjects: 0106 biological sciences, 0301 basic medicine, Lipopolysaccharides, General Physics and Astronomy, Oligosaccharides, Chitin, 01 natural sciences, Plant Roots, Cell Wall, Gene Expression Regulation, Plant, Mycorrhizae, Plant symbiosis, Plant Immunity, Arbuscular mycorrhiza, lcsh:Science, Plant Proteins, Regulation of gene expression, Multidisciplinary, biology, Cell Death, Kinase, food and beverages, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, Medicago truncatula, Cell biology, 3. Good health, Signalling, Signal Transduction, Science, Protein Serine-Threonine Kinases, Article, General Biochemistry, Genetics and Molecular Biology, Cell wall, 03 medical and health sciences, Symbiosis, Tobacco, Pattern recognition receptors in plants, Chitosan, fungi, General Chemistry, biochemical phenomena, metabolism, and nutrition, biology.organism_classification, Plant Leaves, 030104 developmental biology, lcsh:Q, Function (biology), [SDV.EE.IEO]Life Sciences [q-bio]/Ecology, environment/Symbiosis, 010606 plant biology & botany
Abstract: Plants associate with beneficial arbuscular mycorrhizal fungi facilitating nutrient acquisition. Arbuscular mycorrhizal fungi produce chitooligosaccharides (COs) and lipo-chitooligosaccharides (LCOs), that promote symbiosis signalling with resultant oscillations in nuclear-associated calcium. The activation of symbiosis signalling must be balanced with activation of immunity signalling, which in fungal interactions is promoted by COs resulting from the chitinaceous fungal cell wall. Here we demonstrate that COs ranging from CO4-CO8 can induce symbiosis signalling in Medicago truncatula. CO perception is a function of the receptor-like kinases MtCERK1 and LYR4, that activate both immunity and symbiosis signalling. A combination of LCOs and COs act synergistically to enhance symbiosis signalling and suppress immunity signalling and receptors involved in both CO and LCO perception are necessary for mycorrhizal establishment. We conclude that LCOs, when present in a mix with COs, drive a symbiotic outcome and this mix of signals is essential for arbuscular mycorrhizal establishment., Polysaccharide molecules chitooligosaccharides (COs) and peptidoglycan not only activate plant immunity but also trigger plant symbiosis signalling. Here the authors show that a combination of COs and lipochitooligosaccharides (LCOs) act synergistically to suppress immunity and promote symbiosis to facilitate beneficial fungal associations.
Published: 2019
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15. The surface chemistry of a nanocellulose drug carrier unravelled by MAS-DNP

Author: Isabelle Baussanne, Daniel Lee, Sabine Hediger, Sébastien Fort, Cyril Balsollier, Akshay Kumar, Bastien Watbled, Julien Bras, Cécile Sillard, Naceur Belgacem, Gaël De Paëpe, Hippolyte Durand, Martine Demeunynck, Elisa Zeno, Magnetic Resonance (RM ), Modélisation et Exploration des Matériaux (MEM), 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 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 Génie des procédés papetiers (LGP2), Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Université Grenoble Alpes (UGA), Centre Technique du Papier (CTP), Centre de Recherches sur les Macromolécules Végétales (CERMAV), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Département de pharmacochimie moléculaire (DPM), Centre National de la Recherche Scientifique (CNRS), and ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017)
Subjects: Conductometry, Chemistry(all), Nanotechnology, 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, 3. Good health, Nanocellulose, chemistry.chemical_compound, Chemistry, Adsorption, chemistry, Covalent bond, Drug delivery, Surface modification, [CHIM]Chemical Sciences, Cellulose, 0210 nano-technology, Drug carrier
Abstract: Cellulose nanofibrils (CNF) are renewable bio-based materials with high specific area, which makes them ideal candidates for multiple emerging applications including for instance on-demand drug release. However, in-depth chemical and structural characterization of the CNF surface chemistry is still an open challenge, especially for low weight percentage of functionalization. This currently prevents the development of efficient, cost-effective and reproducible green synthetic routes and thus the widespread development of targeted and responsive drug-delivery CNF carriers. We show in this work how we use dynamic nuclear polarization (DNP) to overcome the sensitivity limitation of conventional solid-state NMR and gain insight into the surface chemistry of drug-functionalized TEMPO-oxidized cellulose nanofibrils. The DNP enhanced-NMR data can report unambiguously on the presence of trace amounts of TEMPO moieties and depolymerized cellulosic units in the starting material, as well as coupling agents on the CNFs surface (used in the heterogeneous reaction). This enables a precise estimation of the drug loading while differentiating adsorption from covalent bonding (∼1 wt% in our case) as opposed to other analytical techniques such as elemental analysis and conductometric titration that can neither detect the presence of coupling agents, nor differentiate unambiguously between adsorption and grafting. The approach, which does not rely on the use of 13C/15N enriched compounds, will be key to further develop efficient surface chemistry routes and has direct implication for the development of drug delivery applications both in terms of safety and dosage., DNP-enhanced solid-state NMR unravels the surface chemistry of functionalized nanocellulose.
Published: 2021
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16. Optimizing Chitin Depolymerization by Lysozyme to Long-Chain Oligosaccharides

Author: Sylvie Armand, Luc Choisnard, Antoine Rousseau, Stéphanie Pradeau, Laurine Buon, Laure Fort, Arnaud Masselin, Rodolphe Gueret, Sylvain Cottaz, Sébastien Fort, Centre de Recherches sur les Macromolécules Végétales (CERMAV), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Département de Chimie Moléculaire (DCM), Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Département de pharmacochimie moléculaire (DPM)
Subjects: 0106 biological sciences, QH301-705.5, Microorganism, Pharmaceutical Science, Oligosaccharides, Chitin, 01 natural sciences, Article, response surface methodology, 03 medical and health sciences, chemistry.chemical_compound, Enzymatic hydrolysis, Drug Discovery, Response surface methodology, Biology (General), Pharmacology, Toxicology and Pharmaceutics (miscellaneous), lysozyme, 030304 developmental biology, 2. Zero hunger, 0303 health sciences, Depolymerization, Hydrolysis, fungi, Acetylation, 15. Life on land, chitin oligosaccharides, [CHIM.POLY]Chemical Sciences/Polymers, chemistry, Biochemistry, Yield (chemistry), Muramidase, Lysozyme, chemo-enzymatic synthesis, 010606 plant biology & botany
Abstract: International audience; Chitin oligosaccharides (COs) hold high promise as organic fertilizers in the ongoing agro-ecological transition. Short- and long-chain COs can contribute to the establishment of symbiotic associations between plants and microorganisms, facilitating the uptake of soil nutrients by host plants. Long-chain COs trigger plant innate immunity. A fine investigation of these different signaling pathways requires improving the access to high-purity COs. Here, we used the response surface methodology to optimize the production of COs by enzymatic hydrolysis of water-soluble chitin (WSC) with hen egg-white lysozyme. The influence of WSC concentration, its acetylation degree, and the reaction time course were modelled using a Box–Behnken design. Under optimized conditions, water-soluble COs up to the nonasaccharide were formed in 51% yield and purified to homogeneity. This straightforward approach opens new avenues to determine the complex roles of COs in plants.
Published: 2021
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17. A New Route to NAG‐NAM Disaccharide, an Important Building Block for Peptidoglycan Oligomer Synthesis

Author: Isabelle Jeacomine, Sylvie Armand, Emeline Richard, Sébastien Fort, Sylvain Cottaz, Antoine Rousseau, Centre de Recherches sur les Macromolécules Végétales (CERMAV), and Institut de Chimie du CNRS (INC)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: chemistry.chemical_classification, 010405 organic chemistry, Chemistry, Stereochemistry, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Organic Chemistry, Disaccharide, Oligosaccharide, peptidoglycan, 010402 general chemistry, 01 natural sciences, Pentapeptide repeat, Oligomer, chitinbiose, Bacterial cell structure, 0104 chemical sciences, carbohydrates (lipids), chemistry.chemical_compound, Enzyme, muropeptide, oligosaccharide, selective deacylation, Peptidoglycan
Abstract: International audience; Peptidoglycan oligomers constitute precious tools for the biochemical and structural studies of enzymes involved in the bacterial cell wall metabolism. In this study we show that an unprecedented selective Zemplén de-O-acetylation of benzyl chitinbioside peracetate leads to a fast and efficient route to N-acetylmuramyl β(1→4) N-acetylglucosaminide disaccharide, a central building block for the synthesis of peptidoglycan oligomers. Starting from known benzyl chitinbioside, NAG-NAM disaccharide pentapeptide is prepared in seven steps with an overall yield of 12%.
Published: 2021
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18. Size‐controlled synthesis of β(1→4)‐GlcNAc oligosaccharides using an endo‐glycosynthase

Author: Sébastien Fort, Sylvie Armand, Antoine Rousseau, Sylvain Cottaz, Centre de Recherches sur les Macromolécules Végétales (CERMAV), and Institut de Chimie du CNRS (INC)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDV.BIO]Life Sciences [q-bio]/Biotechnology, Lysine, Oligosaccharides, Chitin, Peptidoglycan, 01 natural sciences, Catalysis, Pichia pastoris, 03 medical and health sciences, chemistry.chemical_compound, Animals, Glycosyl, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, Glucosamine, 0303 health sciences, Sinorhizobium meliloti, biology, 010405 organic chemistry, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Pathogen-associated molecular pattern, Organic Chemistry, General Chemistry, Glycosynthase, biology.organism_classification, 0104 chemical sciences, carbohydrates (lipids), chemistry, Biochemistry
Abstract: Chitin and peptidoglycan fragments are well recognized as pathogen associated molecular patterns (PAMPs). Long-chain oligosaccharides of β(1→4)-linked N-acetyl-D-glucosamine (GlcNAc) units indeed activate plants and mammals innate immune system. However, the mechanisms underlying PAMPs perception by lysine motif (LysM) domain receptors remain largely unknown because of insufficient availability of high-affinity molecular probes. Here, we report a two-enzyme cascade to synthesize long-chain β(1→4)-linked GlcNAc oligomers. Expression of the D52S mutant of hen egg-white lysozyme (HEWL) in Pichia pastoris at 52 mg L-1 provided a new glycosynthase catalyzing efficient polymerization of α-chitintriosyl fluoride. Selective N-deacetylation at the non-reducing unit of the glycosyl fluoride donor by Sinorhizobium meliloti NodB chitin-N-deacetylase abolished its ability to be polymerized by the glycosynthase but not to be transferred onto an acceptor. Using NodB and D52S HEWL in a one-pot cascade reaction allowed the synthesis on a milligram scale of chitin hexa-, hepta- and octasaccharides with yields up to 65 % and a perfect control over their size.
Published: 2021
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19. Distinct genetic bases for plant root responses to lipo-chitooligosaccharide signal molecules from distinct microbial origins

Author: Magali Garcia, Christophe Jacquet, Maxime Bonhomme, Sébastien Fort, Guillaume Bécard, Emilie Amblard, Fabienne Maillet, Sandra Bensmihen, Virginie Puech-Pagès, Sylvain Cottaz, Clare Gough, Olivier André, Centre de Recherches sur les Macromolécules Végétales (CERMAV), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Laboratoire de Recherche en Sciences Végétales (LRSV), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire des Interactions Plantes Microbes Environnement (LIPME), Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut de Chimie du CNRS (INC)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), ANR-14-CE18-0008,NICE CROPS,Bio-stimulateurs chitiniques naturels pour une agriculture durable(2014), ANR-11-INBS-0010,METABOHUB,Développement d'une infrastructure française distribuée pour la métabolomique dédiée à l'innovation(2011), ANR-11-LABX-0003,ARCANE,Grenoble, une chimie bio-motivée(2011), ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017), ANR-15-IDEX-0002,UGA,IDEX UGA(2015), ANR-16-CRNT-0005,Innovation Chimie Carnot,Innovation Chimie Carnot(2016), and ANR-10-LABX-0041,TULIP,Towards a Unified theory of biotic Interactions: the roLe of environmental(2010)
Subjects: 0106 biological sciences, [SDV]Life Sciences [q-bio], Genome-wide association study, Nod, 01 natural sciences, lateral root development, Rhizobia, [SDV.GEN.GPL]Life Sciences [q-bio]/Genetics/Plants genetics, 03 medical and health sciences, lipo-chitooligosaccharides, Medicago truncatula, GWAS, [CHIM]Chemical Sciences, Legume, 030304 developmental biology, Genetics, 0303 health sciences, biology, fungi, Plant root, food and beverages, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, Heritability, biology.organism_classification, Phenotype, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, Nod Factors, 010606 plant biology & botany
Abstract: SummaryLipo-chitooligosaccharides (LCOs) were originally found as symbiotic signals called Nod Factors (Nod-LCOs) controlling nodulation of legumes by rhizobia. More recently LCOs were also found in symbiotic fungi and, more surprisingly, very widely in the kingdom fungi including in saprophytic and pathogenic fungi. The LCO-V(C18:1, Fuc/MeFuc), hereafter called Fung-LCOs, are the LCO structures most commonly found in fungi. This raises the question of how legume plants, such asMedicago truncatula, can perceive and discriminate between Nod-LCOs and these Fung-LCOs.To address this question, we performed a Genome Wide Association Study on 173 natural accessions ofMedicago truncatula, using a root branching phenotype and a newly developed local score approach.Both Nod- and Fung-LCOs stimulated root branching in most accessions but there was very little correlation in the ability to respond to these types of LCO molecules. Moreover, heritability of root response was higher for Nod-LCOs than for Fung-LCOs. We identified 123 loci for Nod-LCO and 71 for Fung-LCO responses, but only one was common.This suggests that Nod- and Fung-LCOs both control root branching but use different molecular mechanisms. The tighter genetic constraint of the root response to Fung-LCOs possibly reflects the ancestral origin of the biological activity of these molecules.
Published: 2020
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20. Ligand-recognizing motifs in plant LysM receptors are major determinants of specificity

Author: Damiano Lironi, Simon Boje Hansen, Maria Vinther, Feng Feng, Giles E. D. Oldroyd, Zoltan Bozsoki, Christian Kofoed, Sébastien Fort, John T. Sullivan, Manoj Kamble, Ebbe Engholm, Knud J. Jensen, Noor de Jong, Kira Gysel, Clive W. Ronson, Christina Krönauer, Mikkel B. Thygesen, Mickaël Blaise, Simona Radutoiu, Kasper R. Andersen, Jens Stougaard, Centre de Recherches sur les Macromolécules Végétales (CERMAV), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Sainsbury Laboratory Cambridge University (SLCU), University of Cambridge [UK] (CAM), and Aarhus University [Aarhus]
Subjects: 0106 biological sciences, [SDV]Life Sciences [q-bio], Lotus japonicus, Protein domain, Amino Acid Motifs, Chitin, Nod, Biology, Ligands, 01 natural sciences, Nod factor, 03 medical and health sciences, chemistry.chemical_compound, Symbiosis, Protein Domains, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, [CHIM]Chemical Sciences, Receptor, 030304 developmental biology, Plant Proteins, 0303 health sciences, Multidisciplinary, fungi, food and beverages, biology.organism_classification, Cell biology, chemistry, Lotus, Protein Kinases, Intracellular, 010606 plant biology & botany
Abstract: Switching perception of friend and foe Lysine motif receptors in plants perceive glycans that signal the presence of pathogenic or symbiotic nitrogen-fixing microbes. Bozsoki et al. now define the portions of these receptors that create the discriminatory binding pocket (see the Perspective by Bisseling and Geurts). The motifs were conserved in receptors that initiate immune responses, reflecting the invariable nature of the chitin fragments that they sense. Conversely, the motifs in receptors that respond to symbiotic signals were more varied, reflecting the greater diversity of the lipochitooligosaccharides (Nod factors) that they sense. With domain swapping, the authors switched the Nod factor specificity of receptors from two legume species and also enabled a chitin receptor that was otherwise dedicated to the detection of pathogenic microbes to instead recognize Nod factors. Science , this issue p. 663 ; see also p. 620
Published: 2020
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21. A LysM effector subverts chitin‐triggered immunity to facilitate arbuscular mycorrhizal symbiosis

Author: Virginie Gasciolli, Sylvain Cottaz, Willy A. M. van den Berg, Bart P. H. J. Thomma, Jean Jacques Bono, Erik Limpens, Sébastien Fort, Tian Zeng, Artem Mansurkhodzaev, Luis Rodriguez-Moreno, Peng Wang, Ton Bisseling, Wageningen University and Research [Wageningen] (WUR), Centre de Biologie pour la Gestion des Populations (UMR CBGP), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Université de Montpellier (UM)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Centre de Recherches sur les Macromolécules Végétales (CERMAV), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), Federation de Recherche Agrobiosciences, Interactions et Biodiversite (FR 3450), CNRS, Universite de Toulouse, UPS, Castanet-Tolosan, France, Institut National de la Recherche Agronomique (INRA), IDEX 'UNITI' Universite de Toulouse (GO-AHEAD project), European Project: 294790,EC:FP7:ERC,ERC-2011-ADG_20110310,PARAEVOLUTION(2012), Laboratoire des Interactions Plantes Microbes Environnement (LIPME), Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut de Chimie du CNRS (INC)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Wageningen University and Research Centre [Wageningen] (WUR), Institut Jean-Pierre Bourgin (IJPB), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), and Chemisch Biologisch Laboratorium Bodem
Subjects: 0106 biological sciences, 0301 basic medicine, Rhizophagus irregularis, Physiology, [SDV]Life Sciences [q-bio], Amino Acid Motifs, LysM, Lysin, Oligosaccharides, Plant Science, 01 natural sciences, Biochemistry, chemistry.chemical_compound, Mycorrhizae, Mycelium, ComputingMilieux_MISCELLANEOUS, Vegetal Biology, biology, Full Paper, Effector, arbuscular mycorrhiza, Chitinases, food and beverages, Full Papers, Medicago truncatula, symbiosis, Cell biology, effector, Host-Pathogen Interactions, Laboratory of Molecular Biology, plant immunity, Genes, Fungal, Biochemie, chitin, Cell wall, Fungal Proteins, 03 medical and health sciences, Chitin, Symbiosis, Laboratorium voor Moleculaire Biologie, Amino Acid Sequence, Gene Silencing, Glomeromycota, Chitosan, Lysine, Research, fungi, biology.organism_classification, Laboratorium voor Phytopathologie, 030104 developmental biology, chemistry, Laboratory of Phytopathology, EPS, Biologie végétale, 010606 plant biology & botany
Abstract: International audience; Arbuscular mycorrhizal (AM) fungi greatly improve mineral uptake by host plants in nutrient-depleted soil and can intracellularly colonize root cortex cells in the vast majority of higher plants. However, AM fungi possess common fungal cell wall components such as chitin that can be recognized by plant chitin receptors to trigger immune responses, raising the question as to how AM fungi effectively evade chitin-triggered immune responses during symbiosis. In this study, we characterize a secreted lysin motif (LysM) effector identified from the model AM fungal species Rhizophagus irregularis, called RiSLM. RiSLM is one of the highest expressed effector proteins in intraradical mycelium during the symbiosis. In vitro binding assays show that RiSLM binds chitin-oligosaccharides and can protect fungal cell walls from chitinases. Moreover, RiSLM efficiently interferes with chitin-triggered immune responses, such as defence gene induction and reactive oxygen species production in Medicago truncatula. Although RiSLM also binds to symbiotic (lipo)chitooligosaccharides it does not interfere significantly with symbiotic signalling in Medicago. Host-induced gene silencing of RiSLM greatly reduces fungal colonization levels. Taken together, our results reveal a key role for AM fungal LysM effectors to subvert chitin-triggered immunity in symbiosis, pointing to a common role for LysM effectors in both symbiotic and pathogenic fungi.
Published: 2020
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22. Neuraminidase activity of blue eye disease porcine rubulavirus: Specificity, affinity and inhibition studies

Author: Bernard Priem, Julio Reyes-Leyva, Humberto Ramírez-Mendoza, Gerardo Santos-López, María del Tránsito Borraz-Argüello, Sébastien Fort, Juan Carlos Flores-Alonso, Irma Herrera-Camacho, Verónica Vallejo-Ruiz, Luis Márquez-Domínguez, Facultad de Medicina Veterinaria y Zootecnia. Universidad Nacional Autónoma de México, Centre de Recherches sur les Macromolécules Végétales (CERMAV ), and Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: 0301 basic medicine, Swine, [SDV]Life Sciences [q-bio], Neuraminidase, Sialidase, Virus, Microbiology, Viral Proteins, 03 medical and health sciences, chemistry.chemical_compound, Zanamivir, medicine, Animals, HN Protein, Rubulavirus, ComputingMilieux_MISCELLANEOUS, Swine Diseases, General Veterinary, biology, Rubulavirus Infections, biology.organism_classification, Virology, 3. Good health, Sialic acid, Kinetics, 030104 developmental biology, chemistry, biology.protein, Hemagglutinin-neuraminidase, medicine.drug
Abstract: Porcine rubulavirus (PorPV), also known as La Piedad Michoacan Virus (LPMV) causes encephalitis and reproductive failure in newborn and adult pigs, respectively. The hemagglutinin-neuraminidase (HN) glycoprotein is the most exposed and antigenic of the virus proteins. HN plays central roles in PorPV infection; i.e., it recognizes sialic acid-containing cell receptors that mediate virus attachment and penetration; in addition, its neuraminidase (sialic acid releasing) activity has been proposed as a virulence factor. This work describes the purification and characterization of PorPV HN protein (isolate PAC1). The specificity of neuraminidase is restricted to sialyl(α2,3)lactose (3SL). HN showed typical Michaelis-Menten kinetics with fetuin as substrate (km=0.029μM, Vmax=522.8nmolmin-1mg-1). When 3SL was used as substrate, typical cooperative kinetics were found (S50=0.15μM, Vmax=154.3nmolmin-1mg-1). The influenza inhibitor zanamivir inhibited the PorPV neuraminidase with IC50 of 0.24μM. PorPV neuraminidase was activated by Ca2+ and inhibited by nucleoside triphosphates with the level of inhibition depending on phosphorylation level. The present results open possibilities to study the role of neuraminidase in the pathogenicity of PorPV infection and its potential inhibitors.
Published: 2017
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23. Unprecedented Affinity Labeling of Carbohydrate-Binding Proteins with

Author: Arnaud, Masselin, Antoine, Petrelli, Maxime, Donzel, Sylvie, Armand, Sylvain, Cottaz, and Sébastien, Fort
Subjects: Staining and Labeling, Triazines, Receptors, Cell Surface, Glycosides
Abstract: Carbohydrate-protein interactions trigger a wide range of biological signaling pathways, the mainstays of physiological and pathological processes. However, there are an incredible number of carbohydrate-binding proteins (CBPs) that remain to be identified and characterized. This study reports for the first time the covalent labeling of CBPs by triazinyl glycosides, a new and promising class of affinity-based glycoprobes. Mono- and bis-clickable triazinyl glycosides were efficiently synthesized from unprotected oligosaccharides (chitinpentaose and 2'-fucosyl-lactose) in a single step. These molecules allow the specific covalent labeling of chitin-oligosaccharide-binding proteins (wheat germ agglutinin WGA and
Published: 2019

24. Unprecedented Affinity Labeling of Carbohydrate-Binding Proteins with s -Triazinyl Glycosides

Author: Sylvain Cottaz, Maxime Donzel, Arnaud Masselin, Sébastien Fort, Sylvie Armand, Antoine Petrelli, Centre de Recherches sur les Macromolécules Végétales (CERMAV ), and Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: musculoskeletal diseases, Pharmacology, chemistry.chemical_classification, Biological signaling, 0303 health sciences, Affinity labeling, Organic Chemistry, Biomedical Engineering, Pharmaceutical Science, Glycoside, Bioengineering, 010402 general chemistry, 01 natural sciences, 3. Good health, 0104 chemical sciences, 03 medical and health sciences, chemistry, Biochemistry, [CHIM]Chemical Sciences, Carbohydrate-responsive element-binding protein, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, Biotechnology
Abstract: Carbohydrate–protein interactions trigger a wide range of biological signaling pathways, the mainstays of physiological and pathological processes. However, there are an incredible number of carboh...
Published: 2019
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25. Discovery of processive catalysis by an exo-hydrolase with a pocket-shaped active site

Author: Jean-Didier Maréchal, José-Emilio Sánchez-Aparicio, Igor Tvaroška, Jose N. Varghese, Maria Hrmova, José M. Lluch, Sukanya Luang, V.A. Streltsov, A. Peisley, Marcel Hijnen, Jesús Jiménez-Barbero, Ana Ardá, J.R. Ketudat Cairns, Laura Tiessler-Sala, Carme Rovira, Fernanda Mendoza, Mercedes Alfonso-Prieto, Jaime Rodríguez-Guerra, Sébastien Fort, Laura Masgrau, Centre de Recherches sur les Macromolécules Végétales (CERMAV ), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institute of Chemistry, Centre for Glycomics, Slovak Academy of Science [Bratislava] (SAS), Catalytic Spectroscopy Laboratory (CSIC), Institute of Catalysis and Petroleum Chemistry, Departament de Quimica Fisica and Institut de Quimica Teorica i Computacional (IQTCUB), Universitat de Barcelona (UB), and Universitat Autònoma de Barcelona (UAB)
Subjects: 0301 basic medicine, Models, Molecular, Computational chemistry, Science, General Physics and Astronomy, 02 engineering and technology, Molecular Dynamics Simulation, Crystallography, X-Ray, General Biochemistry, Genetics and Molecular Biology, Article, Catalysis, Substrate Specificity, 03 medical and health sciences, Molecular dynamics, NMR spectroscopy, Catalytic Domain, Hydrolase, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Glycosides, lcsh:Science, Nuclear Magnetic Resonance, Biomolecular, Alkyl, ComputingMilieux_MISCELLANEOUS, Enzyme Assays, Plant Proteins, X-ray crystallography, chemistry.chemical_classification, Multidisciplinary, biology, Active site, Substrate (chemistry), Hordeum, General Chemistry, 021001 nanoscience & nanotechnology, Recombinant Proteins, 030104 developmental biology, Enzyme, chemistry, Biocatalysis, Seedlings, Enzyme mechanisms, biology.protein, Biophysics, lcsh:Q, Molecular modelling, 0210 nano-technology, Glucosidases
Abstract: Substrates associate and products dissociate from enzyme catalytic sites rapidly, which hampers investigations of their trajectories. The high-resolution structure of the native Hordeum exo-hydrolase HvExoI isolated from seedlings reveals that non-covalently trapped glucose forms a stable enzyme-product complex. Here, we report that the alkyl β-d-glucoside and methyl 6-thio-β-gentiobioside substrate analogues perfused in crystalline HvExoI bind across the catalytic site after they displace glucose, while methyl 2-thio-β-sophoroside attaches nearby. Structural analyses and multi-scale molecular modelling of nanoscale reactant movements in HvExoI reveal that upon productive binding of incoming substrates, the glucose product modifies its binding patterns and evokes the formation of a transient lateral cavity, which serves as a conduit for glucose departure to allow for the next catalytic round. This path enables substrate-product assisted processive catalysis through multiple hydrolytic events without HvExoI losing contact with oligo- or polymeric substrates. We anticipate that such enzyme plasticity could be prevalent among exo-hydrolases., Enzyme substrates and products often diffuse too rapidly to assess the catalytic implications of these movements. Here, the authors characterise the structural basis of product and substrate diffusion for an exo-hydrolase and discover a substrate-product assisted processive catalytic mechanism.
Published: 2019
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26. Bacterial synthesis of polysialic acid lactosides in recombinantEscherichia coliK-12

Author: Bernard Priem, Sophie Drouillard, Laurine Buon, Sébastien Fort, Emeline Richard, Centre de Recherches sur les Macromolécules Végétales (CERMAV ), and Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: 0301 basic medicine, Glycosylation, [SDV.BIO]Life Sciences [q-bio]/Biotechnology, [SDV]Life Sciences [q-bio], Lactosylceramides, Polysaccharide, medicine.disease_cause, 01 natural sciences, Biochemistry, Gene Expression Regulation, Enzymologic, law.invention, 03 medical and health sciences, chemistry.chemical_compound, law, Gangliosides, medicine, Glycosides, Escherichia coli, ComputingMilieux_MISCELLANEOUS, chemistry.chemical_classification, Escherichia coli K12, 010405 organic chemistry, Polysialic acid, Polysaccharides, Bacterial, Carbohydrate, Recombinant Proteins, Sialyltransferases, 0104 chemical sciences, Sialic acid, 030104 developmental biology, Enzyme, chemistry, Sialic Acids, Click chemistry, Recombinant DNA
Abstract: Bacterial polysialyltransferases (PSTs) are processive enzymes involved in the synthesis of polysialic capsular polysaccharides. They can also synthesize polysialic acid in vitro from disialylated and trisialylated lactoside acceptors, which are the carbohydrate moieties of GD3 and GT3 gangliosides, respectively. Here, we engineered a non-pathogenic Escherichia coli strain that overexpresses recombinant sialyltransferases and sialic acid synthesis genes and can convert an exogenous lactoside into polysialyl lactosides. Several PSTs were assayed for their ability to synthesize polysialyl lactosides in the recombinant strains. Fed-batch cultures produced α-2,8 polysialic acid or alternate α-2,8-2,9 polysialic acid in quantities reaching several grams per liter. Bacterial culture in the presence of propargyl-β-lactoside as the exogenous acceptor led to the production of conjugatable polysaccharides by means of copper-assisted click chemistry.
Published: 2016
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27. Enzymatically Activated Glyco-Prodrugs of Doxorubicin Synthesized by a Catalysis-Free Diels–Alder Reaction

Author: P. Leblond, Sébastien Fort, Martine Demeunynck, Samuel Meignan, David Bliman, Isabelle Baussane, Centre de Recherches sur les Macromolécules Végétales (CERMAV ), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Département de pharmacochimie moléculaire (DPM ), Plasticité Cellulaire et Cancer - U908 (CPAC), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lille, Fort, Sébastien, and Université de Lille-Institut National de la Santé et de la Recherche Médicale (INSERM)
Subjects: Anthracycline, Plasmin, medicine.medical_treatment, Biomedical Engineering, Pharmaceutical Science, Oligosaccharides, Bioengineering, Antineoplastic Agents, Breast Neoplasms, 010402 general chemistry, 01 natural sciences, chemistry.chemical_compound, [CHIM] Chemical Sciences, medicine, Humans, [CHIM]Chemical Sciences, Doxorubicin, Prodrugs, Fibrinolysin, Diels–Alder reaction, Pharmacology, Protease, 010405 organic chemistry, Organic Chemistry, Prodrug, In vitro, 3. Good health, 0104 chemical sciences, Xyloglucan, chemistry, Biochemistry, MCF-7 Cells, Drug Screening Assays, Antitumor, Carboxylic Ester Hydrolases, Biotechnology, medicine.drug
Abstract: International audience; The severe side effects associated with the use of anthracycline anticancer agents continues to limit their use. Herein we describe the synthesis and preliminary biological evaluation of three enzymatically activatable doxorubicin-oligosaccharide prodrugs. The synthetic protocol allows late stage variation of the carbohydrate and is compatible with the use of disaccharides such as lactose as well as more complex oligosaccharides such as xyloglucan oligomers. The enzymatic release of doxorubicin from the prodrugs by both protease (plasmin) and human carboxylesterases (hCE1 and 2) was demonstrated in vitro and the cytotoxic effect of the prodrugs were assayed on MCF-7 breast cancer cells.
Published: 2018
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28. Chemoenzymatic Syntheses of Sialylated Oligosaccharides Containing C5-Modified Neuraminic Acids for Dual Inhibition of Hemagglutinins and Neuraminidases

Author: Eric Samain, Julio Reyes-Leyva, Sébastien Fort, Gerardo Santos-López, Lémonia Birikaki, Sylvie Armand, Hugues Driguez, Stéphanie Pradeau, Bernard Priem, Luis Márquez-Domínguez, Centre de Recherches sur les Macromolécules Végétales (CERMAV), and Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)
Subjects: endocrine system, Stereochemistry, [SDV]Life Sciences [q-bio], Neuraminidase, Oligosaccharides, medicine.disease_cause, Sialidase, Catalysis, chemistry.chemical_compound, Agglutinin, Neuraminic acid, Escherichia coli, medicine, [CHIM]Chemical Sciences, Animals, Maackia, Vibrio cholerae, ComputingMilieux_MISCELLANEOUS, Ganglioside, biology, Chemistry, Hydrolysis, Organic Chemistry, General Chemistry, biology.organism_classification, carbohydrates (lipids), Hemagglutinins, Metabolic Engineering, Biochemistry, Agglutinins, Sialic Acids, biology.protein, Cattle, Neuraminic Acids, lipids (amino acids, peptides, and proteins)
Abstract: A fast chemoenzymatic synthesis of sialylated oligosaccharides containing C5-modified neuraminic acids is reported. Analogues of GM3 and GM2 ganglioside saccharidic portions where the acetyl group of NeuNAc has been replaced by a phenylacetyl (PhAc) or a propanoyl (Prop) moiety have been efficiently prepared with metabolically engineered E. coli bacteria. GM3 analogues were either obtained by chemoselective modification of biosynthetic N-acetyl-sialyllactoside (GM3 NAc) or by direct bacterial synthesis using C5-modified neuraminic acid precursors. The latter strategy proved to be very versatile as it led to an efficient synthesis of GM2 analogues. These glycomimetics were assessed against hemagglutinins and sialidases. In particular, the GM3 NPhAc displayed a binding affinity for Maackia amurensis agglutinin (MAA) similar to that of GM3 NAc, while being resistant to hydrolysis by Vibrio cholerae (VC) neuraminidase. A preliminary study with influenza viruses also confirmed a selective inhibition of N1 neuraminidase by GM3 NPhAc, suggesting potential developments for the detection of flu viruses and for fighting them.
Published: 2015
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29. DMTMM-mediated amidation of alginate oligosaccharides aimed at modulating their interaction with proteins

Author: Sébastien Fort, Sophie Mathieu, Pierre Yves Morvan, Patricia Chaud, Romuald Vallee, Flavien Labre, William Helbert, Département de Chimie Moléculaire - Synthèse Et Réactivité en Chimie Organique (DCM - SeRCO ), Département de Chimie Moléculaire (DCM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Centre de Recherches sur les Macromolécules Végétales (CERMAV ), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), CNRS, and Centre National de la Recherche Scientifique (CNRS)
Subjects: Magnetic Resonance Spectroscopy, Polymers and Plastics, Rhamnose, Mannose, Oligosaccharides, 02 engineering and technology, Alginate oligosaccharides, 010402 general chemistry, 01 natural sciences, chemistry.chemical_compound, Hydrolysis, Non-competitive inhibition, Alginate lyases, Lectins, Amidation, Materials Chemistry, Concanavalin A, [CHIM]Chemical Sciences, Polysaccharide-Lyases, Alanine, chemistry.chemical_classification, biology, Organic Chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Amino acid, chemistry, Biochemistry, Multivalency, biology.protein, Leucine, 0210 nano-technology, Lectin
Abstract: International audience; 10 Alginate oligosaccharides (AOS) with a weight average molecular weight of 5 kDa were 11 efficiently amidated with amino acids and carbohydrates in aqueous media in the presence of 12 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM). Here, 13 alanine, leucine, serine, as well as mannose and rhamnose, were amidated at high yields with a 14 good control of the degree of substitution (DS). Amino acid-and carbohydrate-grafted AOS 15 showed improved stability against degradation by alginate lyases having different specificities. 16 This enzyme resistance was correlated with the DS: hydrolysis was reduced by 60 to 70% for 17 low DS (0.1), whereas AOS with DS ranging from 0.4 to 0.6 remained unhydrolyzed. 18 Competitive inhibition assays demonstrated multivalent binding of mannose-amidated AOS to 19 concanavalin A lectin. A 178-fold affinity enhancement was observed for AOSMan-0.38 (DS 0.38) 20 over -methyl-mannoside with an IC50 of 5.6 M, lending further evidence for the promising 21 potential of AOS as multivalent scaffolds. 22 23 24 25 2 Highlights: 26  DMTMM promoted efficient amidation of alginate oligosaccharides (AOS) 27  AOS were functionalized with amino acids and carbohydrates 28  Grafting conferred improved stability to AOS against alginate lyases 29  Mannose-grafted AOS exhibited multivalent inhibition of ConA lectin 30 31
Published: 2017
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30. A versatile nanoarray electrode produced from block copolymer thin films for specific detection of proteins

Author: Edson Minatti, Valdir Soldi, Redouane Borsali, Pierre Labbe, Samira Jamil Fayad, Sébastien Fort, Univ Fed Santa Catarina, Dept Quim, Univ Fed Santa Catarina, Grupo de Estudos em Materiais Poliméricos (POLIMAT), Universidade Federal de Santa Catarina = Federal University of Santa Catarina [Florianópolis] (UFSC), Centre de Recherches sur les Macromolécules Végétales (CERMAV ), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Département de Chimie Moléculaire - Ingéniérie et Intéractions BioMoléculaires (DCM - I2BM), Département de Chimie Moléculaire (DCM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire de Chimie des polymères organiques (LCPO), and Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Université Sciences et Technologies - Bordeaux 1-Institut de Chimie du CNRS (INC)
Subjects: Streptavidin, Materials science, Polymers and Plastics, Organic Chemistry, Supramolecular chemistry, Nanotechnology, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, chemistry.chemical_compound, Nanopore, Ferrocene, chemistry, Materials Chemistry, Copolymer, Molecule, [CHIM]Chemical Sciences, Self-assembly, 0210 nano-technology, Linker, ComputingMilieux_MISCELLANEOUS
Abstract: This work describes how nanostructured thin films obtained from the self-assembly of block copolymers (BCPs) systems can be used as a nanoelectrode array (NEA) that can be programmed to specifically detect targeted molecules. Namely, poly(styrene-b-methacrylate) (PS-b-PMMA) thin films, after removal of PMMA phase, produced regular spaced 560 pores μm-2 with 16 nm of diameter. The nanopores were then chemically modified by the introduction of β-cyclodextrin (β-CD) molecules. By using the supramolecular interaction of β-CD and ferrocene (Fc), the pores could be programed by the introduction of molecules linked to Fc able to interact with target species. In the model system shown here, the linker had a biotin unit, aiming the detection of streptavidin. By changing the linker, other molecules can also be detected. This concept opens a window to many possibilities, including the development of devices for fast and versatile molecule detection.
Published: 2017
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31. Determining the Site of Action of Strigolactones during Nodulation

Author: Erin L. McAdam, Noel W. Davies, Sébastien Fort, CJ Hugill, Sylvain Cottaz, Eric Samain, Eloise Foo, James B. Reid, Centre de Recherches sur les Macromolécules Végétales (CERMAV), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Géoazur (GEOAZUR 7329), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Department of Chemistry [Leicester], University of Leicester, University of Tasmania (UTAS), Centre de Recherches sur les Macromolécules Végétales (CERMAV ), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), and University of Tasmania [Hobart, Australia] (UTAS)
Subjects: 0106 biological sciences, 0301 basic medicine, Lipopolysaccharides, Physiology, [SDV]Life Sciences [q-bio], Mutant, Strigolactone, Down-Regulation, Plant Science, Root hair, 01 natural sciences, Plant Root Nodulation, Plant Roots, Rhizobia, 03 medical and health sciences, Lactones, Plant Growth Regulators, Gene Expression Regulation, Plant, Botany, Genetics, Mode of action, Symbiosis, Transcription factor, ComputingMilieux_MISCELLANEOUS, Plant Proteins, biology, Wild type, Peas, Plant physiology, food and beverages, Articles, Ethylenes, biology.organism_classification, Cell biology, 030104 developmental biology, Phenotype, Mutation, 010606 plant biology & botany, Rhizobium, Signal Transduction, Transcription Factors
Abstract: Strigolactones (SLs) influence the ability of legumes to associate with nitrogen-fixing bacteria. In this study we determine the precise stage at which SLs influence nodulation. We show that SLs promote infection thread formation, as a null SL-deficient pea (Pisum sativum) mutant forms significantly less infection threads than wild type plants and this reduction can be overcome by the application of the synthetic SL GR24. We found no evidence that SLs influence physical events in the plant before or after infection thread formation, since SL-deficient plants displayed a similar ability to induce root hair curling in response to rhizobia or lipochito-oligosaccharides (LCOs) and SL-deficient nodules appear to fix nitrogen at a similar rate to wild type plants. In contrast, a SL receptor mutant displayed no decrease in infection thread formation or nodule number, suggesting SL-deficiency may influence the bacterial partner. We found this influence of SL-deficiency was not due to altered flavonoid exudation or ability of root exudates to stimulate bacterial growth. The influence of SL-deficiency on infection thread formation was accompanied by reduced expression of some early nodulation (ENOD) genes. Importantly, SL synthesis is down-regulated by mutations in genes of the Nod LCO signalling pathway and this requires the downstream transcription factor NSP2 but not NIN. This, together with the fact that the expression of certain SL biosynthesis genes can be elevated in response to rhizobia/Nod factors suggests that Nod LCOs may induce SL biosynthesis. SLs appear to influence nodulation independently of ethylene action, as SL-deficient and ethylene insensitive double mutant plants display essentially additive phenotypes and we found no evidence that SLs influence ethylene synthesis or vice versa.
Published: 2017
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32. Chemobacterial Synthesis of a Sialyl-Tn Cyclopeptide Vaccine Candidate

Author: Emeline Richard, Olivier Renaudet, Eric Samain, Michele Fiore, Carlo Pifferi, Bernard Priem, Sébastien Fort, Audrey Le Gouellec, Laboratoire d'aérologie (LAERO), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Équipe Robotique et InteractionS (LAAS-RIS), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Géoazur (GEOAZUR 7329), Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Centre de Recherches sur les Macromolécules Végétales (CERMAV ), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire des sciences et techniques de l'information, de la communication et de la connaissance (Lab-STICC), École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Télécom Bretagne-Institut Brestois du Numérique et des Mathématiques (IBNM), Université de Brest (UBO)-Université européenne de Bretagne - European University of Brittany (UEB)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-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 Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Université européenne de Bretagne - European University of Brittany (UEB)-École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Télécom Bretagne-Institut Brestois du Numérique et des Mathématiques (IBNM), Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'aérologie (LA), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse 1 Capitole (UT1)-Université Toulouse - Jean Jaurès (UT2J)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse 1 Capitole (UT1)-Université Toulouse - Jean Jaurès (UT2J), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA), Centre de Recherches sur les Macromolécules Végétales (CERMAV), and Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)
Subjects: Glycoconjugate, medicine.drug_class, Enzyme-Linked Immunosorbent Assay, Biology, 010402 general chemistry, medicine.disease_cause, Monoclonal antibody, 01 natural sciences, Biochemistry, Cancer Vaccines, Peptides, Cyclic, Epitope, Microbiology, chemobacterial synthesis, Antigen-Antibody Reactions, Epitopes, Antigen, antigens, medicine, Escherichia coli, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Antigens, Tumor-Associated, Carbohydrate, Amino Acid Sequence, vaccine conjugates, Molecular Biology, Gene, chemistry.chemical_classification, Vaccines, Synthetic, 010405 organic chemistry, Photobacterium, Neisseria meningitidis, sialyl-Tn, Organic Chemistry, Antibodies, Monoclonal, Sialyltransferases, 3. Good health, 0104 chemical sciences, carbohydrates (lipids), chemistry, Metabolic Engineering, Click chemistry, peptides, Molecular Medicine, Click Chemistry, Chromatography, Thin Layer, Neisseria
Abstract: International audience; A conjugatable form of the tumour-associated carbohydrate antigen sialyl-Tn (Neu5Ac-α-2,6-GalNAc) was efficiently produced in Escherichia coli. Metabolically engineered E. coli strains overexpressing the 6-sialyltransferase gene of Photobacterium sp. and CMP-Neu5Ac synthetase genes of Neisseria meningitidis were cultivated at high density in the presence of GalNAc-α-propargyl as the exogenous acceptor. The target disaccharides, which were produced on the scale of several hundreds of milligrams, were then conjugated by using copper(I)-catalysed azide-alkyne cycloaddition click chemistry to a fully synthetic and immunogenic scaffold with the aim to create a candidate anticancer vaccine. Four sialyl-Tn epitopes were introduced on the upper face of an azido-functionalised multivalent cyclopeptide scaffold, the lower face of which was previously modified by an immunogenic polypeptide, PADRE. The ability of the resulting glycoconjugate to interact with oncofoetal sialyl-Tn monoclonal antibodies was confirmed in ELISA assays.
Published: 2017
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33. Efficient Conjugation of Oligosaccharides to Polymer Particles through Furan/Maleimide Diels-Alder Reaction: Application to the Capture of Carbohydrate-Binding Proteins

Author: Eric Samain, Stéphanie Pradeau, Sébastien Fort, Sami Halila, Antoine Petrelli, Centre de Recherches sur les Macromolécules Végétales (CERMAV ), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Géoazur (GEOAZUR 7329), Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Centre de Recherches sur les Macromolécules Végétales (CERMAV), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, and Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)
Subjects: Glycan, Spectrophotometry, Infrared, Polymers, Oligosaccharides, Receptors, Cell Surface, 010402 general chemistry, 01 natural sciences, Biochemistry, Maleimides, Sepharose, chemistry.chemical_compound, Agglutinin, Lectins, Concanavalin A, Furans, Molecular Biology, Maleimide, Diels–Alder reaction, Bioconjugation, Cycloaddition Reaction, biology, 010405 organic chemistry, Organic Chemistry, 3. Good health, 0104 chemical sciences, Glycoproteomics, [CHIM.POLY]Chemical Sciences/Polymers, Microscopy, Fluorescence, chemistry, Click chemistry, biology.protein, Molecular Medicine, Click Chemistry, Fluorescein-5-isothiocyanate, Protein Binding
Abstract: International audience; Glycan-protein interactions play a crucial role in physiological and pathological events. Hence, improving the isolation of carbohydrate-binding proteins (i.e. lectins and anti-glycan antibodies) from complex media can not only lead to a better understanding of their function, but also provides solutions for public health issues, such as water contamination or the need for universal blood plasma. Herein, we report a rapid and efficient method to produce carbohydrate-based affinity adsorbents combining enzymatic synthesis and metal-free click chemistry. Simple as well as complex glycans (maltose, blood group antigens A, B and H) were readily modified by the addition of a furyl group at their reducing end without the need for protecting groups and then efficiently conjugated to maleimide-activated Sepharose particles via a Diels-Alder reaction. These neoglycoconjugates showed high efficiency for the purification of lectins (Concanavalin A and Ulex europaeus agglutinin) as well as for the capture of anti-A and anti-B blood group antibodies, opening new prospects for glycoproteomics and for the development of universal blood plasma.
Published: 2017
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34. Synthesis of Silver Glyconanoparticles from New Sugar-Based Amphiphiles and Their Catalytic Application

Author: Josiel B. Domingos, Sébastien Fort, Brunno L. Albuquerque, Renato Eising, and Welman C. Elias
Subjects: Silver, Surface Properties, Carbohydrates, Oligosaccharides, Nanoparticle, Catalysis, Nitrophenols, Surface tension, chemistry.chemical_compound, Adsorption, Microscopy, Electron, Transmission, Amphiphile, Electrochemistry, Nanotechnology, Scattering, Radiation, Organic chemistry, General Materials Science, Spectroscopy, Ethanol, Sodium, Silver Compounds, Water, Surfaces and Interfaces, Condensed Matter Physics, Solvent, Silver nitrate, chemistry, Chemical engineering, Click chemistry, Nanoparticles, Chromatography, Thin Layer
Abstract: Oligosaccharide-based amphiphiles were readily prepared by click chemistry from ω-azido-hexanoic or dodecanoic acids with propargyl-functionalized maltoheptaose or xyloglucanoligosaccharides. These amphiphilic compounds were used as capping/stabilizer agents in order to obtain highly stable catalytic silver glyconanoparticles (Ag-GNPs) through the in situ reduction of silver nitrate with NaBH4. With a view to long-term storage, the stabilization was optimized using a multivariate approach, and the nanoparticles were characterized by UV-vis, TEM, SAXS, and DLS. In order to explore the functionality of the Ag-GNPs in catalysis, a full kinetic analysis of the reduction of p-nitrophenol by NaBH4 in water and in water/ethanol mixtures was performed under semi-heterogeneous and quasi-homogeneous conditions. A pseudomonomolecular surface reaction was performed, and the kinetic data obtained were treated according to the Langmuir model. The Ag-GNPs were very active, and both substrates adsorbed onto the surface of the nanoparticles. For comparison purposes, the reaction was also performed in the presence of silver-sodium dodecanoate nanoparticles, which showed catalytic activity similar to that of the glyconanoparticles, supporting the choice of the carboxyl group as the stabilizing agent, although it provided much lower temporal stability. Finally, by combining kinetic and water/ethanol surface tension data it was possible to observe the effect of the addition of the less polar solvent (ethanol) to the reaction medium.
Published: 2014
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35. Nod Factor Effects on Root Hair-Specific Transcriptome of Medicago truncatula: Focus on Plasma Membrane Transport Systems and Reactive Oxygen Species Networks

Author: Vincent Maillol, Alexandre Boscari, Etienne Danchin, Eric Samain, Isabelle Damiani, Bruno Touraine, Jean-Marie Frachisse, Alain Puppo, Véronique Brunaud, Isabelle Gaillard, Sylvain Cottaz, Alice Drain, Martine Da Rocha, Jean-Christophe Boyer, Hervé Sentenac, Hatem Rouached, Marjorie Guichard, Corinne Rancurel, Sandrine Balzergue, Sébastien Fort, Yanhua Su, Nicolas Pauly, Julien Thouin, Cécile Fizames, Institut Sophia Agrobiotech (ISA), Centre National de la Recherche Scientifique (CNRS)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut National de la Recherche Agronomique (INRA), Biochimie et Physiologie Moléculaire des Plantes (BPMP), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Institute for Integrative Biology of the Cell, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences des Plantes de Paris-Saclay (IPS2 (UMR_9213 / UMR_1403)), Institut National de la Recherche Agronomique (INRA)-Université Paris-Sud - Paris 11 (UP11)-Université Paris Diderot - Paris 7 (UPD7)-Université d'Évry-Val-d'Essonne (UEVE)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherches sur les Macromolécules Végétales (CERMAV ), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Méthodes et Algorithmes pour la Bioinformatique (MAB), Laboratoire d'Informatique de Robotique et de Microélectronique de Montpellier (LIRMM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), State Key Laboratory of Soil and Sustainable Agriculture, Chinese Academy of Sciences [Beijing] (CAS)-Institute of Soil Science, Institut Sophia Agrobiotech [Sophia Antipolis] (ISA), Institut National de la Recherche Agronomique (INRA)-Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Université de Montpellier (UM)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Institut National de la Recherche Agronomique (INRA)-Université d'Évry-Val-d'Essonne (UEVE)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Saclay-Université Paris-Sud - Paris 11 (UP11), Centre de Recherches sur les Macromolécules Végétales (CERMAV), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Pauly, Nicolas, Sentenac, Herve, Institut National de la Recherche Agronomique (INRA)-Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), and Institut de Biologie Intégrative de la Cellule (I2BC)
Subjects: 0106 biological sciences, 0301 basic medicine, Plant Science, lcsh:Plant culture, racine aérienne, Root hair, 01 natural sciences, root hairs, Nod factor, Transcriptome, Nod factors (lipochitooligosaccharides), 03 medical and health sciences, reactive oxygen species, Symbiosis, symbiose rhizobium legumineuse, Medicago truncatula, Botany, Rhizobial Symbiosis, Root Hairs, Plasma Membrane Transpor, Reactive Oxygen, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, lcsh:SB1-1110, transport membranaire, Gene, Original Research, Calcium signaling, Vegetal Biology, biology, Membrane transport, deep-RNA sequencing, biology.organism_classification, Cell biology, legume-rhizobium symbiosis, 030104 developmental biology, plasma membrane transport systems, Biologie végétale, 010606 plant biology & botany
Abstract: International audience; Root hairs are involved in water and nutrient uptake, and thereby in plant autotrophy. In legumes, they also play a crucial role in establishment of rhizobial symbiosis. To obtain a holistic view of Medicago truncatula genes expressed in root hairs and of their regulation during the first hours of the engagement in rhizobial symbiotic interaction, a high throughput RNA sequencing on isolated root hairs from roots challenged or not with lipochitooligosaccharides Nod factors (NF) for 4 or 20 h was carried out. This provided a repertoire of genes displaying expression in root hairs, responding or not to NF, and specific or not to legumes. In analyzing the transcriptome dataset, special attention was paid to pumps, transporters, or channels active at the plasma membrane, to other proteins likely to play a role in nutrient ion uptake, NF electrical and calcium signaling, control of the redox status or the dynamic reprogramming of root hair transcriptome induced by NF treatment, and to the identification of papilionoid legume-specific genes expressed in root hairs. About 10% of the root hair expressed genes were significantly up- or down-regulated by NF treatment, suggesting their involvement in remodeling plant functions to allow establishment of the symbiotic relationship. For instance, NF-induced changes in expression of genes encoding plasma membrane transport systems or disease response proteins indicate that root hairs reduce their involvement in nutrient ion absorption and adapt their immune system in order to engage in the symbiotic interaction. It also appears that the redox status of root hair cells is tuned in response to NF perception. In addition, 1176 genes that could be considered as "papilionoid legume-specific" were identified in the M. truncatula root hair transcriptome, from which 141 were found to possess an ortholog in every of the six legume genomes that we considered, suggesting their involvement in essential functions specific to legumes. This transcriptome provides a valuable resource to investigate root hair biology in legumes and the roles that these cells play in rhizobial symbiosis establishment. These results could also contribute to the long-term objective of transferring this symbiotic capacity to non-legume plants.
Published: 2016
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36. Tunable Aggregation and Gelation of Thermoresponsive Suspensions of Polymer-Grafted Cellulose Nanocrystals

Author: Roumaïssa Hassaini, Eder Siqueira, Christophe Travelet, Frédéric Pignon, Firas Azzam, Jean-Luc Putaux, Bruno Jean, Sébastien Fort, Centre de Recherches sur les Macromolécules Végétales (CERMAV ), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire des Écoulements Géophysiques et Industriels [Grenoble] (LEGI ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire de rhéologie (LR), Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Université Joseph Fourier - Grenoble 1 (UJF), Centre de recherche sur le développement territorial (CRDT), and Centre de recherche sur le développement territorial
Subjects: Materials science, Polymers and Plastics, Polymers, Bioengineering, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, Biomaterials, chemistry.chemical_compound, Colloid, Dynamic light scattering, Suspensions, Polymer chemistry, Materials Chemistry, Thermal stability, Cellulose, ComputingMilieux_MISCELLANEOUS, Dichloromethane, chemistry.chemical_classification, Aggregation number, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, Osmolar Concentration, Temperature, Water, Polymer, 021001 nanoscience & nanotechnology, 0104 chemical sciences, chemistry, Chemical engineering, Covalent bond, Ionic strength, Nanoparticles, 0210 nano-technology, [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft], Gels, Hydrophobic and Hydrophilic Interactions
Abstract: The colloidal stability together with the tunable aggregation and viscoelastic properties of thermoresponsive polymer-grafted cellulose nanocrystals (CNCs) were investigated. TEMPO oxidation of CNCs followed by peptidic coupling in water were used to covalently graft thermosensitive Jeffamine polyetheramine M2005 chains onto the surface of CNCs. The resulting polymer-decorated particles (M2005-g-CNCs) exhibited new colloidal properties, by their ability to perfectly redisperse in water and organic solvents such as toluene, dichloromethane or DMF after freeze-drying. In addition, they presented an enhanced thermal stability when compared to that of sulfated or TEMPO-oxidized CNCs. Dynamic light scattering experiments were used to demonstrate that the thermally induced aggregation of M2005-g-CNCs was fully reversible and reproducible over many temperature cycles and that, most interestingly, the aggregation number could be tuned by varying the ionic strength and/or the pH of the medium, making the suspension multiresponsive. This property arises from the variations of the sign (attractive or repulsive) and the range of the different types (entropic, electrostatic, hydrophobic) of interaction forces between the thermosensitive polymer-decorated nanoparticles. The variation of the viscoelastic properties of M2005-g-CNCs suspensions as a function of temperature, probed by oscillatory rheology measurements of more concentrated suspensions, revealed a reversible temperature-triggered liquid-to-gel transition. Such enhanced functionalities pave the way to the design of advanced CNC-based materials benefiting both from the intrinsic characteristics of these biosourced particles and the new properties imparted by the stimuli-sensitive grafted chains.
Published: 2016

37. The molecular basis of polysaccharide cleavage by lytic polysaccharide monooxygenases

Author: Esther M. Johnston, Gideon J. Davies, Laurence Marmuse, Morten Tovborg, Leila Lo Leggio, Bernard Henrissat, Katja Salomon Johansen, Floriana Tuna, Amgalanbaatar Baldansuren, Paul H. Walton, Luisa Ciano, Hugues Driguez, Pernille von Freiesleben, Sébastien Fort, Glyn R. Hemsworth, Jens-Christian N. Poulsen, Thomas J. Simmons, Paul Dupree, Sylvain Cottaz, Kristian E. H. Frandsen, Nicolas Lenfant, Architecture et fonction des macromolécules biologiques (AFMB), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), UK Biotechnology and Biological Sciences Research Council [BB/L000423, BB/L021633/1], Agence Francaise de l'Environnement et de la Maitrise de l'Energie [1201C102], Danish Council for Strategic Research [12-134923, 12-134922], European Community [283570], Institut de Chimie Moleculaire de Grenoble [FR 2607], LabEx ARCANE [ANR-11-LABX-0003-01], PolyNat Carnot Institute, French Agence Nationale de la Recherche [PNRB2005-11], Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Dupree, Paul [0000-0001-9270-6286], Hemsworth, Glyn R [0000-0002-8226-1380], Ciano, Luisa [0000-0002-1667-0856], Baldansuren, Amgalanbaatar [0000-0001-8767-3731], Davies, Gideon J [0000-0002-7343-776X], Lo Leggio, Leila [0000-0002-5135-0882], Walton, Paul H [0000-0002-1152-1480], and Apollo - University of Cambridge Repository
Subjects: 0301 basic medicine, Models, Molecular, conformation, coordination, oxygenases, Aspergillus oryzae, Oligosaccharides, Chitin, Lentinula, Crystallography, X-Ray, Mixed Function Oxygenases, Substrate Specificity, chemistry.chemical_compound, Catalytic Domain, Fluorescence Resonance Energy Transfer, ComputingMilieux_MISCELLANEOUS, chemistry.chemical_classification, biology, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], [SDV.BIBS]Life Sciences [q-bio]/Quantitative Methods [q-bio.QM], [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biomolecules [q-bio.BM], Biochemistry, Oxidation-Reduction, Molecular Sequence Data, mechanism, Polysaccharide, chemistry, Article, 03 medical and health sciences, cellulose degradation, Oxidoreductase, Amino Acid Sequence, Cellulose, Molecular Biology, Binding Sites, Active site, Cell Biology, Monooxygenase, enzyme, 030104 developmental biology, Enzyme, substrate-specificity, biology.protein, activation, Copper, discovery
Abstract: Lytic polysaccharide monooxygenases (LPMOs) are copper-containing enzymes which oxidatively break down recalcitrant polysaccharides such as cellulose and chitin. Since their discovery LPMOs have become integral factors in the industrial utilization of biomass, especially in the sustainable generation of cellulosic bioethanol. We report here the first structural determination of an LPMO–oligosaccharide complex, yielding detailed insights into the mechanism of action of these enzymes. Using a combination of structure and electron paramagnetic resonance spectroscopy, we reveal the means by which LPMOs interact with saccharide substrates. We further uncover electronic and structural features of the enzyme active site, showing how LPMOs orchestrate the reaction of oxygen with polysaccharide chains.
Published: 2016
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38. Redox tunable delivery systems: sweet block copolymer micelles via thiol–(bromo)maleimide conjugation

Author: Sami Halila, Antoine Petrelli, Sébastien Fort, Redouane Borsali, Centre de Recherches sur les Macromolécules Végétales (CERMAV ), and Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Micelle, Catalysis, chemistry.chemical_compound, Polymer chemistry, Materials Chemistry, Copolymer, [CHIM]Chemical Sciences, Maleimide, ComputingMilieux_MISCELLANEOUS, chemistry.chemical_classification, Aqueous solution, Metals and Alloys, Nile red, General Chemistry, Oligosaccharide, 021001 nanoscience & nanotechnology, 0104 chemical sciences, 3. Good health, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, chemistry, Polycaprolactone, Ceramics and Composites, Thiol, 0210 nano-technology
Abstract: Oligosaccharide-based block copolymers (OBCPs) are synthesized by thiol click conjugation using reducing-end thiol-containing xyloglucooligosaccharides and maleimide- or bromomaleimide-terminated polycaprolactone. The self-assembled OBCPs in aqueous solution lead to redox-sensitive micelles with different responsiveness. This distinguishing feature allows us to control the release of entrapped hydrophobic Nile red by mixing both OBCPs.
Published: 2016
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39. The microRNA miR171h modulates arbuscular mycorrhizal colonization ofMedicago truncatulaby targetingNSP2

Author: Jean-Philippe Combier, Christine Lelandais-Brière, Pierre-Marc Delaux, Christophe Roux, Sébastien Fort, Damien Formey, Andreas Niebel, Sylvain Cottaz, Dominique Lauressergues, and Guillaume Bécard
Subjects: 0106 biological sciences, Rhizophagus irregularis, Regulation of gene expression, 0303 health sciences, biology, fungi, Mutant, Cell Biology, Plant Science, Fungus, biochemical phenomena, metabolism, and nutrition, 15. Life on land, biology.organism_classification, 01 natural sciences, Medicago truncatula, Glomeromycota, 03 medical and health sciences, Symbiosis, Botany, Genetics, Colonization, 030304 developmental biology, 010606 plant biology & botany
Abstract: Most land plants live symbiotically with arbuscular mycorrhizal fungi. Establishment of this symbiosis requires signals produced by both partners: strigolactones in root exudates stimulate pre-symbiotic growth of the fungus, which releases lipochito-oligosaccharides (Myc-LCOs) that prepare the plant for symbiosis. Here, we have investigated the events downstream of this early signaling in the roots. We report that expression of miR171h, a microRNA that targets NSP2, is up-regulated in the elongation zone of the root during colonization by Rhizophagus irregularis (formerly Glomus intraradices) and in response to Myc-LCOs. Fungal colonization was much reduced by over-expressing miR171h in roots, mimicking the phenotype of nsp2 mutants. Conversely, in plants expressing an NSP2 mRNA resistant to miR171h cleavage, fungal colonization was much increased and extended into the elongation zone of the roots. Finally, phylogenetic analyses revealed that miR171h regulation of NSP2 is probably conserved among mycotrophic plants. Our findings suggest a regulatory mechanism, triggered by Myc-LCOs, that prevents over-colonization of roots by arbuscular mycorrhizal fungi by a mechanism involving miRNA-mediated negative regulation of NSP2.
Published: 2012
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40. Thermoresponsive Self-Assemblies of Cyclic and Branched Oligosaccharide-block-poly(N-isopropylacrylamide) Diblock Copolymers into Nanoparticles

Author: Redouane Borsali, Issei Otsuka, Sébastien Fort, Sami Halila, Isabelle Pignot-Paintrand, Christophe Travelet, Atsushi Narumi, Centre de Recherches sur les Macromolécules Végétales (CERMAV), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), inconnu, and Inconnu
Subjects: Materials science, Polymers and Plastics, Polymers, Acrylic Resins, Oligosaccharides, Nanoparticle, Bioengineering, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Catalysis, Biomaterials, chemistry.chemical_compound, Polymer chemistry, Materials Chemistry, Copolymer, Molecule, ComputingMilieux_MISCELLANEOUS, Acrylamides, Molecular Structure, Atom-transfer radical-polymerization, Temperature, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Field electron emission, Crystallography, [CHIM.POLY]Chemical Sciences/Polymers, chemistry, Cyclization, Transmission electron microscopy, Poly(N-isopropylacrylamide), Nanoparticles, Azide, 0210 nano-technology, Copper
Abstract: This paper discusses the thermoresponsive nanoparticles obtained by self-assemblies of nonlinear oligosaccharide-based diblock copolymer systems. These diblock copolymers were synthesized by Cu(I)-catalyzed 1,3-dipolar azide/alkyne cycloaddition ("click" reaction) of propargyl-functionalized β-cyclodextrin (βCyD) and xyloglucooligosaccharide (XGO) with poly(N-isopropylacrylamide) (PNIPAM) having a terminal azido group prepared by atom transfer radical polymerization (ATRP). Elastic and quasi-elastic light scattering analysis of the dibock copolymers in H(2)O indicated that thermodynamic phase transitions of the PNIPAM blocks at their cloud points (T(cp)s ≈ 34 °C), around lower critical solution temperatures (LCSTs), triggered their self-assemblies into the nanoparticles. These nanoparticles had narrow size distributions and small interphases (i.e., sharp boundaries). The mean hydrodynamic radii (R(h)s) of the βCyD and XGO-based nanoparticles were determined to be around 150 and 250 nm upon slow heating (i.e., step-by-step heating), and 364 and 91.5 nm upon fast heating, respectively, depending on a predominance of the interchain association or the intrachain contraction. Transmission electron microscope (TEM) and field emission gun-scanning electron microscopy (FEG-SEM) images of the nanoparticles clearly showed compact spherical nanoparticles whose cores are mainly made with the PNIPAM blocks, whereas the rough shells consist in the oligosaccharidic blocks.
Published: 2012
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41. Self-Assembly of Amphiphilic Glycoconjugates into Lectin-Adhesive Nanoparticles

Author: Alexandre Gonçalves Dal Bó, Sébastien Fort, Bruno Jean, Christophe Travelet, Fernando C. Giacomelli, Isabelle Pignot-Paintrand, Redouane Borsali, and Valdir Soldi
Subjects: Peanut agglutinin, Micelle, Microscopy, Electron, Transmission, X-Ray Diffraction, Dynamic light scattering, Adhesives, Lectins, Scattering, Small Angle, Amphiphile, PEG ratio, Electrochemistry, Organic chemistry, General Materials Science, Spectroscopy, biology, Small-angle X-ray scattering, Chemistry, Vesicle, Surfaces and Interfaces, Condensed Matter Physics, Wheat germ agglutinin, Chemical engineering, Microscopy, Electron, Scanning, biology.protein, Nanoparticles, Glycoconjugates
Abstract: This work describes the synthesis and self-assembly of carbohydrate-clicked rod-coil amphiphilic systems. Copper-catalyzed Huisgen cycloaddition was efficiently employed to functionalize the hydrophilic extremity of PEG-b-tetra(p-phenylene) conjugates by lactose and N-acetyl-glucosamine ligands. The resulting amphiphilic systems spontaneously self-assembled into nanoparticles when dissolved in aqueous media, as evidenced by dynamic light scattering (DLS), transmission electron microscopy (TEM), and small-angle X-ray scattering (SAXS). The formation of highly monodisperse micelles having a mean diameter of 10 nm was observed for systems containing a PEG 900 core, and a decrease in the hydrophilic moiety (PEG 600) led to the formation of vesicles with a broader size distribution. The presence of carbohydrate residues on the surfaces of the micelles and their ability to establish specific interactions with wheat germ agglutinin (WGA) and peanut agglutinin (PNA) were further highlighted by light-scattering measurements, thus confirming the attractive applications of such sugar micelles in biosensor devices.
Published: 2011
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42. Development of Catalytically Active Silver Colloid Nanoparticles Stabilized by Dextran

Author: Josiel B. Domingos, Renato Eising, Sébastien Fort, and Aline M. Signori
Subjects: Silver, Surface Properties, Composite number, Inorganic chemistry, Metal Nanoparticles, Nanoparticle, Salt (chemistry), Borohydrides, Catalysis, Metal, chemistry.chemical_compound, Reaction rate constant, Electrochemistry, General Materials Science, Colloids, Particle Size, Spectroscopy, chemistry.chemical_classification, technology, industry, and agriculture, Dextrans, Surfaces and Interfaces, Condensed Matter Physics, Kinetics, Dextran, Silver colloid, chemistry, Chemical engineering, visual_art, visual_art.visual_art_medium, Oxidation-Reduction
Abstract: Colloidal silver nanoparticles (Ag-NPs) with a mean diameter of 6.1 nm and a narrow size distribution were prepared by reduction of the correspondent metal salt with injection of NaBH(4), in the presence of dextran, and characterized by UV-vis, TEM, and DLS. The concentration of all reactants involved in the formation of the nanoparticles was optimized with the use of a new multivariate method, which revealed a significant reduction in the number of experiments when compared with the vast majority of univariate methods described in the literature. The Ag-NPs-dextran composite was able to efficiently catalyze the p-nitrophenol reduction in water by NaBH(4) with a rate constant normalized to the surface area of the nanoparticles per unit volume (k(1)) of 1.41 s(-1) m(-2) L, which is higher than values ever reported for Ag-NPs catalytic systems.
Published: 2011
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43. Chemo-bacterial synthesis and immunoreactivity of a brain HNK-1 analogue

Author: Ludovic Bastide, Bernard Priem, Sébastien Fort, Carret, Michèle, Centre de Recherches sur les Macromolécules Végétales (CERMAV), and Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)
Subjects: Molecular Sequence Data, Allyl compound, Oligosaccharides, Enzyme-Linked Immunosorbent Assay, 010402 general chemistry, medicine.disease_cause, 01 natural sciences, Biochemistry, Epitope, Analytical Chemistry, 03 medical and health sciences, CD57 Antigens, Sulfation, Escherichia coli, medicine, Humans, Trisaccharide, Bovine serum albumin, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, chemistry.chemical_classification, 0303 health sciences, biology, Immunodominant Epitopes, Organic Chemistry, Brain, Serum Albumin, Bovine, General Medicine, Oligosaccharide, 0104 chemical sciences, 3. Good health, Allyl Compounds, Carbohydrate Sequence, chemistry, biology.protein, Antibody, Trisaccharides
Abstract: This work reports the synthesis and the biological validation of a trisaccharide analogue of the HNK-1 epitope. The 3-O-sulfo-β-d-GlcpA-(1→3)-β-d-Galp-(1→4)-β-d-Glcp-allyl has been prepared by enzymatic glucuronylation of allyl lactoside by an engineered recombinant Escherichia coli strain followed by a chemoselective sulfation. Subsequent covalent attachment of the ozone-oxidised trisaccharide to bovine serum albumin provided a neo-glycoconjugate, which has been interrogated with antibodies specific to the human natural killer carbohydrate epitope HNK-1. ELISA assays confirmed the absolute requirement of the sulfate group for protein recognition and the potential application of this synthetic oligosaccharide as HNK-1 surrogate.
Published: 2011
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44. Syntheses of Well-Defined Glyco-Polyorganosiloxanes by 'Click' Chemistry and their Surfactant Properties

Author: Maggy Manguian, Etienne Fleury, Hugues Driguez, Sami Halila, Sylvain Cottaz, Sébastien Fort, and Thierry Hamaide
Subjects: Polymers and Plastics, 010405 organic chemistry, Chemistry, Organic Chemistry, 010402 general chemistry, Condensed Matter Physics, 01 natural sciences, Coupling reaction, Cycloaddition, 0104 chemical sciences, Catalysis, End-group, chemistry.chemical_compound, Polymer chemistry, 1,3-Dipolar cycloaddition, Materials Chemistry, Click chemistry, Organic chemistry, Azide, Physical and Theoretical Chemistry, Solubility
Abstract: Well-defined glyco-polyorganosiloxanes were synthesized by the Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition reaction (often simply referred to as "click" chemistry). N-propargylglycosylamines 2 and 4 were first synthesized from cellobiose (1) and xylogluco-oligosaccharide XGOs 3 without protecting groups. The azide function was introduced into polydimethylsiloxanes [PDMS: 5 (MD'M) and 7 (M'DM')] by azidolysis of the counterpart epoxy silicon with NaN 3 to afford the mono-azido 6 and di-azido 8 derivatives, respectively. The coupling reaction took place in a hydro-alcoholic medium in the presence of CuSO 4 /sodium ascorbate as catalyst. Only one compound, MD'M-"click"-XGO 12 showed good solubility in water with interesting surfactant properties.
Published: 2008
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45. Activation of Symbiosis Signaling by Arbuscular Mycorrhizal Fungi in Legumes and Rice

Author: Enrico Gobbato, Eric Samain, Jean-Michel Ané, Fabienne Maillet, Richard J. Morris, Muthusubramanian Venkateshwaran, Jongho Sun, Emma Granqvist, Sylvain Cottaz, Giles E. D. Oldroyd, Sébastien Fort, Audrey Wiley-Kalil, Jean Dénarié, J. Benjamin Miller, Cell and Developmental Biology, John Innes Centre [Norwich], Biologie et Génétique des Interactions Plante-Parasite (UMR BGPI), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro), Laboratoire des interactions plantes micro-organismes (LIPM), Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherches sur les Macromolécules Végétales (CERMAV), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Department of Primary Care and Population Health [London] (PCPH), University College of London [London] (UCL), Department of Bacteriology, Veterinary Laboratories Agency, European Research Council as 'SYMBIOSIS,' the Bill and Melinda Gates Foundation, the Biotechnology and Biological Sciences Research Council as BB/J004553/1, Labex Arcane, ICMG as FR2607, and the Gatsby Charitable Foundation as a Sainsbury PhD fellowship, Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), and Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)
Subjects: Lipopolysaccharides, 0106 biological sciences, [SDV]Life Sciences [q-bio], Molecular Sequence Data, Lotus japonicus, Oligosaccharides, chemistry.chemical_element, Chitin, Plant Science, Fungus, Calcium, 01 natural sciences, 03 medical and health sciences, Symbiosis, Gene Expression Regulation, Plant, Mycorrhizae, Medicago truncatula, Botany, Calcium Signaling, Research Articles, ComputingMilieux_MISCELLANEOUS, Glucuronidase, 030304 developmental biology, Chitosan, 0303 health sciences, Oryza sativa, biology, Lateral root, fungi, food and beverages, Oryza, Cell Biology, biology.organism_classification, chemistry, Seedlings, Lotus, Bacteria, Signal Transduction, 010606 plant biology & botany
Abstract: Establishment of arbuscular mycorrhizal interactions involves plant recognition of diffusible signals from the fungus, including lipochitooligosaccharides (LCOs) and chitooligosaccharides (COs). Nitrogen-fixing rhizobial bacteria that associate with leguminous plants also signal to their hosts via LCOs, the so-called Nod factors. Here, we have assessed the induction of symbiotic signaling by the arbuscular mycorrhizal (Myc) fungal-produced LCOs and COs in legumes and rice (Oryza sativa). We show that Myc-LCOs and tetra-acetyl chitotetraose (CO4) activate the common symbiosis signaling pathway, with resultant calcium oscillations in root epidermal cells of Medicago truncatula and Lotus japonicus. The nature of the calcium oscillations is similar for LCOs produced by rhizobial bacteria and by mycorrhizal fungi; however, Myc-LCOs activate distinct gene expression. Calcium oscillations were activated in rice atrichoblasts by CO4, but not the Myc-LCOs, whereas a mix of CO4 and Myc-LCOs activated calcium oscillations in rice trichoblasts. In contrast, stimulation of lateral root emergence occurred following treatment with Myc-LCOs, but not CO4, in M. truncatula, whereas both Myc-LCOs and CO4 were active in rice. Our work indicates that legumes and non-legumes differ in their perception of Myc-LCO and CO signals, suggesting that different plant species respond to different components in the mix of signals produced by arbuscular mycorrhizal fungi.
Published: 2015
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46. New glycosylated conjugate copolymer N-acetyl-β-D-glucosaminyl-pluronic: Synthesis, self-assembly and biological assays

Author: Tiago Elias Allievi Frizon, José Luiz Westrup, Adriani Paganini Damiani, Luiza Martins Longaretti, Sébastien Fort, Yasmine Miguel Serafini Micheletto, Fernando C. Giacomelli, Priscila Sayoko Silva Wakabayashi, Vanessa Moraes de Andrade, Francieli Rocha Serafim, Alexandre Gonçalves Dal Bó, Centre de Recherches sur les Macromolécules Végétales (CERMAV), and Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)
Subjects: Hydrodynamic radius, Glycosylation, 02 engineering and technology, Poloxamer, 010402 general chemistry, 01 natural sciences, Micelle, Acetylglucosamine, Colloid and Surface Chemistry, Microscopy, Electron, Transmission, X-Ray Diffraction, Scattering, Small Angle, Zeta potential, Copolymer, Organic chemistry, [CHIM]Chemical Sciences, Humans, Physical and Theoretical Chemistry, ComputingMilieux_MISCELLANEOUS, Micelles, Small-angle X-ray scattering, Chemistry, Surfaces and Interfaces, General Medicine, 021001 nanoscience & nanotechnology, 0104 chemical sciences, carbohydrates (lipids), Crystallography, Spectrometry, Fluorescence, Critical micelle concentration, Thermodynamics, Comet Assay, 0210 nano-technology, Biotechnology, Conjugate
Abstract: This work describes the synthesis of a new glycosylated conjugate copolymer, GlcNAc-PEO75-PPO30-PEO75-GlcNAc (GlcNAc-PluronicF68-GlcNAc), using click chemistry from Pluronic® F68 and propargyl-2-N-acetamido-2-deoxy-β- d -glucopyranoside. Micelles were prepared by the self-assembly of GlcNAc-PluronicF68-GlcNAc in phosphate-buffered solution. The critical micelle concentration was determined by fluorescence spectroscopy, and the value was found to be equal to 5.8 mg mL−1. The Gibbs free energy (ΔG) of micellization is negative, indicating that the organization of amphiphiles is governed by the hydrophobic effects in an entropy-driven process. The scattering characterization of GlcNAc-PluronicF68-GlcNAc micelles showed a hydrodynamic radius of 8.7 nm and negative zeta potential (−21.0 ± 0.9 mV). The TEM image evidences the spherical shape of the objects self-assemble into highly regular micelles having a mean diameter of 10 nm. The SAXS profile confirmed the spherical shape of the assemblies comprising a swollen PPO core (Rcore = 2.25 nm) stabilized by PEO chains following Gaussian statistics. The results of the comet assay showed that the GlcNAc-PluronicF68-GlcNAc micelles were not genotoxic, and the cell viability test was higher than 97% for all concentrations, demonstrating that GlcNAc-PluronicF68-GlcNAc is not toxic.
Published: 2015
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47. Carbohydrates as New Probes for the Identification of Closely Related Escherichia coli Strains Using Surface Plasmon Resonance Imaging

Author: Emilie Bulard, Patricia Chaud, Aurélie Bouchet-Spinelli, Sébastien Fort, André Roget, Roberto Calemczuk, Thierry Livache, Chimie pour la Reconnaissance et l’Etude d’Assemblages Biologiques (CREAB), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-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)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-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)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherches sur les Macromolécules Végétales (CERMAV), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), ANR-11-LABX-0003,ARCANE,Grenoble, une chimie bio-motivée(2011), 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), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-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), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Food Safety, Colony Count, Microbial, Food Contamination, 02 engineering and technology, Escherichia coli O157, medicine.disease_cause, 01 natural sciences, Analytical Chemistry, O157-H7, Foodborne Diseases, Lectins, Surface plasmon resonance imaging, Escherichia coli, medicine, Humans, Biochip, Escherichia coli Infections, [PHYS]Physics [physics], biology, Bacteria, Chemistry, 010401 analytical chemistry, Equipment Design, Surface Plasmon Resonance, Contamination, Microarray Analysis, 021001 nanoscience & nanotechnology, biology.organism_classification, O157H7, 0104 chemical sciences, Recognition, Biochemistry, Tissue Array Analysis, Molecular Probes, Microelectrode Array Biosensor, Food Microbiology, Carbohydrate Metabolism, Gold surface, Pathogens, 0210 nano-technology
Abstract: International audience; Prevention of foodborne diseases depends highly on our ability to control rapidly and accurately a possible contamination of food. So far, standard procedures for bacterial detection require time-consuming bacterial cultures on plates before the pathogens can be detected and identified. We present here an innovative biochip, based on direct differential carbohydrate recognitions of five closely related Escherichia coli strains, including the enterohemorragic E. coli O157:H7. Our device relies on efficient grafting of simple carbohydrates on a gold surface and on the monitoring of their interactions with bacteria during their culture using surface plasmon resonance imaging. We show that each of the bacteria interacts in a different way with the carbohydrate chip. This allows the detection and discrimination of the tested bacterial strains in less than 10 h from an initial bacterial concentration of 102 CFU.mL(-1). This is an improvement over previously described systems in terms of cost, easiness to use, and stability. Easily conceived and easily regenerated, this tool is promising for the future of food safety.
Published: 2015
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48. Discrimination of Different Foodborne Pathogens onto Carbohydrate Microarrays Using Surface Plasmon Resonance Imaging

Author: Aurélie Bouchet-Spinelli, Roberto Calemczuk, Sébastien Fort, Patricia Chaud, Emilie Bulard, Thierry Livache, André Roget, Fort, Sébastien, Institut des Sciences Moléculaires d'Orsay (ISMO), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Chimie pour la Reconnaissance et l’Etude d’Assemblages Biologiques (CREAB), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), 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), 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)-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), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre de Recherches sur les Macromolécules Végétales (CERMAV), Université Joseph Fourier - Grenoble 1 (UJF)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Structures et propriétés d'architectures moléculaire (SPRAM - UMR 5819), Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-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)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-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)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), and Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Salmonella, biology, Microarray, business.industry, [SDV]Life Sciences [q-bio], Pathogenic bacteria, medicine.disease_cause, biology.organism_classification, Food safety, 3. Good health, Microbiology, [SDV] Life Sciences [q-bio], Listeria monocytogenes, [CHIM] Chemical Sciences, medicine, [CHIM]Chemical Sciences, DNA microarray, business, Escherichia coli, Bacteria, ComputingMilieux_MISCELLANEOUS
Abstract: Food safety is a public health challenge. Devices allowing early, fast, label-free and in situ detection of bacteria are of great interest to prevent outbreaks. Listeria monocytogenes, Salmonella spp. and Escherichia coli O157:H7 are foodborne pathogens which were responsible of 60% of the hospitalizations in the USA in 2011. In this study, we conceived a carbohydrate microarray in order to detect and discriminate these three food pathogenic bacteria. In less than 10 hours, from an initial bacterial suspension of 100 bacteria per mL, Surface Plasmon Resonance imaging allowed the detection and the discrimination of these bacteria while they were growing and interacting specifically with the carbohydrate microarray. Moreover, this device is easily regenerable and can be re-used: it is probably a promising tool to early detect bacteria in food.
Published: 2015

49. Efficient chemoenzymatic synthesis of lipo-chitin oligosaccharides as plant growth promoters

Author: Guillaume Despras, A. Brossay, Rémi Chambon, Jean-Marie Beau, Sébastien Fort, Dominique Urban, Sylvie Armand, Boris Vauzeilles, Sylvain Cottaz, Institut de Chimie des Substances Naturelles (ICSN), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Université de Bordeaux (UB), Centre de Recherches sur les Macromolécules Végétales (CERMAV), and Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)
Subjects: chemistry.chemical_classification, 0303 health sciences, 010405 organic chemistry, Stereochemistry, Periplasmic space, Oligosaccharide, medicine.disease_cause, 01 natural sciences, Pollution, Chemical synthesis, In vitro, 0104 chemical sciences, Chitin deacetylase, 03 medical and health sciences, chemistry.chemical_compound, Enzyme, chemistry, Chitin, Biochemistry, Vibrio cholerae, medicine, Environmental Chemistry, [CHIM]Chemical Sciences, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology
Abstract: Lipo-chitin oligosaccharides (Nod and Myc LCOs) are molecules involved in symbiotic phenomena in the plant kingdom. They play a major role in the process of atmospheric nitrogen fixation and mineral soil nutrients uptake both in legumes and in non-legumes, and are active at extremely low concentrations down to the nano- and even picomolar range. These compounds contain various substitutions along the oligosaccharide backbone of the molecule including an essential fatty acid on the non-reducing unit and are considered as environmentally-friendly fertilizers. Currently, chemical synthesis cannot produce precursors of Nod and Myc LCOs at a large scale and an in vitro chemoenzymatic pathway is presented here as a new and efficient method for preparing quantities of these high-value oligosaccharides. VC1280 (Vibrio cholerae) is a chitin deacetylase (CD) capable of regioselectively cleaving an acetate from the non-reducing penultimate N-acetyl-D-glucosaminyl (GlcNAc) unit of chitin oligosaccharides (COs). This provides a free amino group which can be further N-acylated with a fatty-acid chain to give analogues of LCOs. Alternatively, the non-reducing GlcNAc unit can be removed by β-N-acetylglucosaminidase treatment, followed by N-acylation to give natural LCOs. VC1280 CD was produced in the periplasm of E. coli. Under the conditions used, 120 mg of the pure enzyme was recovered from 1 L of culture medium. For the first time, in vitro production of a library of natural LCOs as well as their analogues has been carried out at a preparative scale from biosourced chitin oligosaccharides constituting an approach of major interest for sustainable agriculture.
Published: 2015
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50. Butyrylcholinesterase-catalyzed hydrolysis of N-methylindoxyl acetate: analysis of volume changes upon reaction and hysteretic behavior

Author: Sébastien Fort, Nicole Bec, Patrick Masson, Marie Thérèse Froment, Claude Balny, Fabien Ribes, Lawrence M. Schopfer, Centre de Recherches sur les Macromolécules Végétales (CERMAV), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Génomique et Biotechnologie des Fruits (GBF), Institut National de la Recherche Agronomique (INRA)-École nationale supérieure agronomique de Toulouse [ENSAT]-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Institut de recherche en cancérologie de Montpellier (IRCM - U896 Inserm - UM1), Université Montpellier 1 (UM1)-CRLCC Val d'Aurelle - Paul Lamarque-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure Agronomique de Toulouse-Institut National Polytechnique (Toulouse) (Toulouse INP), and CRLCC Val d'Aurelle - Paul Lamarque-Université de Montpellier (UM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Montpellier 1 (UM1)
Subjects: Models, Molecular, Indoles, Stereochemistry, [SDV]Life Sciences [q-bio], Hydrostatic pressure, Kinetics, Biophysics, Cooperativity, CHO Cells, In Vitro Techniques, Biochemistry, Catalysis, Substrate Specificity, Butyrylthiocholine, 03 medical and health sciences, Hydrolysis, Structural Biology, Catalytic Domain, Cricetinae, Hydrostatic Pressure, Animals, Humans, Enzyme kinetics, Molecular Biology, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 0303 health sciences, biology, Chemistry, 030302 biochemistry & molecular biology, Active site, Recombinant Proteins, Enzyme Activation, Crystallography, Butyrylcholinesterase, Mutagenesis, Site-Directed, biology.protein, Thermodynamics, Salts
Abstract: Hydrolysis of the neutral substrate N-methylindoxyl acetate (NMIA) by wild-type human butyrylcholinesterase (BuChE) and peripheral site mutants (D70G, Y332A, D70G/Y332A) was found to follow the Michaelis-Menten kinetics. K(m) was 0.14 mM for wild-type, and 0.07-0.16 mM for D70G, Y332A and D70G/Y332A, indicating that the peripheral site is not involved in NMIA binding. The values of k(cat) were of the same order for all enzymes: 12,000-18,000 min(-1). Volume changes upon substrate binding (-DeltaV(K(m))) and the activation volumes (DeltaV++(k(cat)) associated with hydrolysis of NMIA were calculated from the pressure dependence of the catalytic constants. Values of -DeltaV(K(m)) indicate that NMIA binds to an aromatic residue, presumed to be W82, the active site binding locus. Binding is accompanied by a release of water molecules from the gorge. Residue 70 controls the number of water molecules that are released upon substrate binding. The values of DeltaV++(k(cat)), which are positive for wild-type and faintly positive for D70G, clearly indicate that the catalytic steps are accompanied by re-entry of water into the gorge. Results support the premise that residue D70 is involved in the conformational stabilization of the active site gorge and in control of its hydration. A slow transient, preceding the steady state, was seen on a time scale of several minutes. The induction time rapidly increased with NMIA concentration to reach a limit at substrate saturation. Much shorter induction times (1 min) were seen for hydrolysis of benzoylcholine (BzCh) by wild-type BuChE and for hydrolysis of butyrylthiocholine (BuSCh) by the active site mutants E197Q and E197Q/G117H. This slow transient was interpreted in terms of hysteresis without kinetic cooperativity. The hysteretic behavior of BuChE results from a slow conformational equilibrium between two enzyme states E and E'. NMIA binds only to the primed form E'. Kosmotropic salts and hydrostatic pressure were found to shift the equilibrium toward E'. The E--E' transition is accompanied by a negative activation volume (DeltaV++(0)= -45+/-10 ml/mol), and the E' form is more compact than E. Hydration water in the gorge of E' appears to be more structured than in the unprimed form.
Published: 2002
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