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3. Identifying the critical role of li substitution in P2-Na x[LiyNizMn1-y-Z]O2 (0 < x, y, z < 1) intercalation cathode materials for high-energy na-ion batteries

Author

Xu, J, Lee, DH, Clément, RJ, Yu, X, Leskes, M, Pell, AJ, Pintacuda, G, Yang, XQ, Grey, CP, and Meng, YS

Subjects
Materials, Chemical Sciences, Engineering
Abstract

Li-substituted layered P2-Na0.80[Li0.12Ni 0.22Mn0.66]O2 is investigated as an advanced cathode material for Na-ion batteries. Both neutron diffraction and nuclear magnetic resonance (NMR) spectroscopy are used to elucidate the local structure, and they reveal that most of the Li ions are located in transition metal (TM) sites, preferably surrounded by Mn ions. To characterize structural changes occurring upon electrochemical cycling, in situ synchrotron X-ray diffraction is conducted. It is clearly demonstrated that no significant phase transformation is observed up to 4.4 V charge for this material, unlike Li-free P2-type Na cathodes. The presence of monovalent Li ions in the TM layers allows more Na ions to reside in the prismatic sites, stabilizing the overall charge balance of the compound. Consequently, more Na ions remain in the compound upon charge, the P2 structure is retained in the high voltage region, and the phase transformation is delayed. Ex situ NMR is conducted on samples at different states of charge/discharge to track Li-ion site occupation changes. Surprisingly, Li is found to be mobile, some Li ions migrate from the TM layer to the Na layer at high voltage, and yet this process is highly reversible. Novel design principles for Na cathode materials are proposed on the basis of an atomistic level understanding of the underlying electrochemical processes. These principles enable us to devise an optimized, high capacity, and structurally stable compound as a potential cathode material for high-energy Na-ion batteries. © 2014 American Chemical Society.

Published
2014

8. Structural and molecular basis of cross-seeding barriers in amyloids

Author

Daskalov, A., primary, Martinez, D., additional, Coustou, V., additional, El Mammeri, N., additional, Berbon, M., additional, Andreas, L.B., additional, Bardiaux, B., additional, Stanek, J., additional, Noubhani, A., additional, Kauffmann, B., additional, Wall, J.S., additional, Pintacuda, G., additional, Saupe, S.J., additional, Habenstein, B., additional, and Loquet, A., additional

Published
2020
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13. To Which Extent Is Paramagnetic Solid-State NMR Able to Address Polymorphism in Complex Transition-Metal Oxides?

Author

Ferrara, C, Ferrari, S, Bini, M, Capsoni, D, Pintacuda, G, Mustarelli, P, Ferrara, C, Ferrari, S, Bini, M, Capsoni, D, Pintacuda, G, and Mustarelli, P

Abstract

A detailed characterization of the polymorphs constituting cathode materials, both before and after cell cycling, is mandatory to develop more stable and powerful lithium batteries. In many cases, e.g., for transition metal lithium silicates, standard diffraction techniques cannot give a clear-cut response. Here we show that broadband adiabatic fast MAS NMR can give unique information in the case of model Li2(Mn,Fe)SiO4 high-capacity cathode materials. By coupling 7Li and 29Si 1D and 2D spectra, we are able to address polymorphs speciation also in the mixed Mn/Fe compositions, which is a nearly impossible task for X-rays and neutrons diffraction. We finally discuss the conditions under which this approach is useful when applied to rare nuclei such as 29Si.

Published
2018

14. Target highlights from the first post-PSI CASP experiment (CASP12, May-August 2016)

Author

Kryshtafovych, A, Albrecht, R, Baslé, A, Bule, P, Caputo, A, Carvalho, A, Chao, K, Diskin, R, Fidelis, K, Fontes, C, Fredslund, F, Gilbert, H, Goulding, C, Hartmann, M, Hayes, C, Herzberg, O, Hill, J, Joachimiak, A, Kohring, G, Koning, R, Lo Leggio, L, Mangiagalli, M, Michalska, K, Moult, J, Najmudin, S, Nardini, M, Nardone, V, Ndeh, D, Nguyen, T, Pintacuda, G, Postel, S, Van Raaij, M, Roversi, P, Shimon, A, Singh, A, Sundberg, E, Tars, K, Zitzmann, N, Schwede, T, Kryshtafovych, A, Albrecht, R, Baslé, A, Bule, P, Caputo, A, Carvalho, A, Chao, K, Diskin, R, Fidelis, K, Fontes, C, Fredslund, F, Gilbert, H, Goulding, C, Hartmann, M, Hayes, C, Herzberg, O, Hill, J, Joachimiak, A, Kohring, G, Koning, R, Lo Leggio, L, Mangiagalli, M, Michalska, K, Moult, J, Najmudin, S, Nardini, M, Nardone, V, Ndeh, D, Nguyen, T, Pintacuda, G, Postel, S, Van Raaij, M, Roversi, P, Shimon, A, Singh, A, Sundberg, E, Tars, K, Zitzmann, N, and Schwede, T

Abstract

The functional and biological significance of the selected CASP12 targets are described by the authors of the structures. The crystallographers discuss the most interesting structural features of the target proteins and assess whether these features were correctly reproduced in the predictions submitted to the CASP12 experiment

Published
2018

15. Functional analysis of Xist-mediated silencing

Author

Pintacuda, G and Brockdorff, N

Abstract

The lncRNA Xist is the master regulator of X chromosome inactivation in female mammals. Its mono-allelic expression triggers a cascade of well characterised events leading to the stable silencing of the X chromosome. However, how Xist coordinates these events is still unclear. We developed a system to dissect Xist function by making a library of deletions of Xist cDNA. The cDNAs were then stably transfected into a male ES cell line under an inducible promoter. The parent cell line was derived from an interspecific cross between different mouse strains, allowing subsequent allele-specific analysis based on a previously described set of strain-specific SNPs. This approach allowed full and partial loss of silencing activity to be discriminated by isolating nascent transcripts upon prolonged Xist expression, and using them to make libraries for high-throughput sequencing. It was therefore possible to map regions of Xist required for specific functions, notably gene silencing and recruitment of Polycomb repressor proteins. Using this approach, the B-repeats were identified as the segment of the RNA crucial for de novo recruitment of both PRC1 and PRC2 Polycomb complexes, whereas the A-repeats were confirmed to be essential for Xist-mediated early silencing of genes. To complement these analyses, an in vitro assembly system was set-up to study the direct interaction between key regions of Xist RNA and defined nuclear proteins at the biochemical/proteomic level, obtaining a comprehensive list of functional candidates. Interestingly, the nuclear matrix protein hnRNP-K was found among the factors significantly enriched over the segment of Xist previously identified as essential for Polycomb recruitment. We thus investigated the functional role of hnRNP-K in mediating the interaction between Xist and Polycomb with a number of in vivo and in vitro assays, and found that hnRNP-K is required to mediate contact between PRC1 and Xist through its KI domain.

Published
2017

16. Solid-state MAS NMR structure of the HELLF prion amyloid fibrils

Author

Martinez, D., primary, Daskalov, A., additional, Andreas, L., additional, Bardiaux, B., additional, Coustou, V., additional, Stanek, J., additional, Berbon, M., additional, Noubhani, M., additional, Kauffmann, B., additional, Wall, J.S., additional, Pintacuda, G., additional, Saupe, S.J., additional, Habenstein, B., additional, and Loquet, A., additional

Published
2018
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17. Solid-state NMR Structure of outer membrane protein G in lipid bilayers

Author

Retel, J.S., primary, Nieuwkoop, A.J., additional, Hiller, M., additional, Higman, V.A., additional, Barbet-Massin, E., additional, Stanek, J., additional, Andreas, L.B., additional, Franks, W.T., additional, van Rossum, B.-J., additional, Vinothkumar, K.R., additional, Handel, L., additional, de Palma, G.G., additional, Bardiaux, B., additional, Pintacuda, G., additional, Emsley, L., additional, Kuelbrandt, W., additional, and Oschkinat, H., additional

Published
2017
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18. Structure and mechanism of the influenza A M2(18-60) dimer of dimers

Author

Andreas, L., Reese, M., Eddy, M., Gelev, V., Ni, Q., Miller, E., Emsley, L., Pintacuda, G., Chou, J., and Griffin, R.

Abstract

We report a magic angle spinning (MAS) NMR structure of the drug-resistant S31N mutation of M2(18-60) from Influenza A. The protein was dispersed in diphytanoyl-sn-glycero-3-phosphocholine lipid bilayers, and the spectra and an extensive set of constraints indicate that M2(18-60) consists of a dimer of dimers. In particular, similar to 280 structural constraints were obtained using dipole recoupling experiments that yielded well-resolved C-13-N-15, C-13-C-13, and H-1-N-15 2D, 3D, and 4D MAS spectra, all of which show cross-peak doubling. Interhelical distances were measured using mixed N-15/C-13 labeling and with deuterated protein, MAS at omega(r)/2 pi = 60 kHz, omega(0H)/2 pi = 1000 MHz, and 11-1 detection of methyl methyl contacts. The experiments reveal a compact structure consisting of a tetramer composed of four transmembrane helices, in which two opposing helices are displaced and rotated in the direction of the membrane normal relative to a four-fold symmetric arrangement, yielding a two-fold symmetric structure. Side chain conformations of the important gating and pH-sensing residues W41 and H37 are found to differ markedly from four-fold symmetry. The rmsd of the structure is 0.7 angstrom for backbone heavy atoms and 1.1 A for all heavy atoms. This two-fold symmetric structure is different from all of the previous structures of M2, many of which were determined in detergent and/or with shorter constructs that are not fully active. The structure has implications for the mechanism of H+ transport since the distance between His and Trp residues on different helices is found to be short. The structure also exhibits two-fold symmetry in the vicinity of the binding site of adamantyl inhibitors, and steric constraints may explain the mechanism of the drug-resistant S31N mutation.

Published
2015

19. A Multitechnique Approach to Spin-Flips for Cp2Cr(II) Chemistry in Confined State

Author

Estephane, J., Groppo, E., Vitillo, J. G., Damin, A., Gianolio, D., Lamberti, C., Bordiga, S., Quadrelli, E. A., Basset, J. M., Kervern, G., Emsley, L., Pintacuda, G., and Zecchina, A.

Abstract

Paramagnetic solid-state NMR, extended X-ray absorption fine structure (EXAFS), and Raman spectroscopies, along with detailed quantum mechanical calculations performed with different density functional theory (DFT) functionals, are successfully applied to investigate the magnetic, structural, and vibrational properties of molecularly isolated chromocene (Cp2Cr, where Cp = C5H5) and of its Cp2Cr(CO) adduct. Paramagnetic solid-state NMR unequivocally demonstrates that a spin flip occurs by coming from the paramagnetic Cp2Cr (triplet state) to the diamagnetic Cp2Cr(CO) adduct (singlet state), thus clarifying the theoretical dilemma of the disagreement among different functionals in predicting the most stable spin state. EXAFS and Raman spectroscopies are able to experimentally discriminate between singlet and triplet states, because a different spin state corresponds to a different geometry of the molecule, and therefore to different vibrational features. The here reported multitechnique approach could have great relevance in establishing the occurrence of spin flip in the chemical reactivity of transition metal complexes in both homo- and heterogeneous catalysis.

Published
2024
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21. Solid-state MAS NMR structure of Acinetobacter phage 205 (AP205) coat protein in assembled capsid particles

Author

Jaudzems, K., primary, Andreas, L.B., additional, Stanek, J., additional, Lalli, D., additional, Bertarello, A., additional, Le Marchand, T., additional, Cala-De Paepe, D., additional, Kotelovica, S., additional, Akopjana, I., additional, Knott, B., additional, Wegner, S., additional, Engelke, F., additional, Lesage, A., additional, Emsley, L., additional, Tars, K., additional, Herrmann, T., additional, and Pintacuda, G., additional

Published
2016
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22. Solid-state MAS NMR structure of immunoglobulin beta 1 binding domain of protein G (GB1)

Author

Andreas, L.B., primary, Jaudzems, K., additional, Stanek, J., additional, Lalli, D., additional, Bertarello, A., additional, Le Marchand, T., additional, Cala-De Paepe, D., additional, Kotelovica, S., additional, Akopjana, I., additional, Knott, B., additional, Wegner, S., additional, Engelke, F., additional, Lesage, A., additional, Emsley, L., additional, Tars, K., additional, Herrmann, T., additional, and Pintacuda, G., additional

Published
2016
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23. Positive experience of intraperitoneal chemotherapy followed by intravenous chemotherapy in heavily pretreated patients with suboptimal residual ovarian cancer and primary peritoneal cancer

Author

Mo, Nicoletto, Dalla Palma M, Me, Donach, milena gusella, Cappetta A, Shams M, Marchet A, Nardin M, Pintacuda G, Di Maggio A, Marchesi M, Carli P, Fiduccia P, Artioli G, and Nitti D

Subjects
Adult, Ovarian Neoplasms, Salvage Therapy, Neoplasm, Residual, Paclitaxel, Cystadenoma, Serous, Ascites, Platinum Compounds, Middle Aged, Survival Analysis, Carcinoma, Papillary, Treatment Outcome, Antineoplastic Combined Chemotherapy Protocols, Feasibility Studies, Humans, Female, Infusions, Parenteral, Neoplasm Recurrence, Local, Infusions, Intravenous, Peritoneal Neoplasms, Aged, Retrospective Studies
Abstract

To assess feasibility and toxicity of intraperitoneal administration of cisplatin and paclitaxel, followed by intravenous chemotherapy in pretreated patients with suboptimal ovarian cancer (residuum1 cm) or primary peritoneal tumor, and suffering from ascites and/or intestinal obstruction.Fourteen relapsed ovarian cancer patients, 5 of whom were platinum sensitive (platinum-free interval6 mo), 7 platinum-resistant (platinum-free interval6 mo), and 2 platinum-refractory, received one cycle of intraperitoneal cisplatin, 100 mg/m2 on day 1, and two cycles of intraperitoneal paclitaxel, 120 mg/m2 on days 8 and 14. Intravenous chemotherapy was administrated 4 weeks following the last intraperitoneal paclitaxel instillation. Blood and peritoneal fluid samples were harvested at 0, 1, 4 and 24 h after ending paclitaxel delivery to guarantee proper tumor exposure and patient safety.Intraperitoneal cisplatin determined 6 cases of vomiting grade 1-2 (40% of the morbidity). Intraperitoneal paclitaxel was associated with 6 events of grade 1-2 abdominal pain; the only grade 4 toxicity was one case of neutropenia and one of mucositis. Ascites decreased in 11 patients: the median time to first need for paracentesis was 5 months, compared to a median baseline paracentesis of 4 weeks. Three intestinal normalizations were obtained. The median overall survival was 10 months for our cohort of patients. Intraperitoneal paclitaxel clearance was significantly higher in patients with suboptimal tumor and symptomatic disease than in patients with smaller residual masses and without ascites (P = 0.004).Intraperitoneal treatment was feasible, and enhanced response to the following intravenous chemotherapy was seen in these patients.

Published
2011

25. Melilite LaSrGa3−xAlxO7Series: A Combined Solid-State NMR and Neutron Diffraction Study

Author

Ferrara, C, Tealdi, C, Mustarelli, P, Hoelzel, M, Pell, A, Pintacuda, G, Pell, AJ, Ferrara, C, Tealdi, C, Mustarelli, P, Hoelzel, M, Pell, A, Pintacuda, G, and Pell, AJ

Abstract

Oxides characterized by a layered melilite structure, with general formula ABT1 (1)T2 (2)O7, find applications in many different technological fields due to their relevant magnetic, optical, and electrical properties. These functional properties are, in turn, related to local features such as structural defects and cation substitutions. Therefore, a complete structural characterization of these complex anisotropic compounds is mandatory, and the combined use of long-range (X-ray and neutron diffraction) and short-range (solid state NMR) techniques is a key approach to this aim. In this work, we present the full structural characterization of the series LaSrGa3-xAlxO7 (x = 0, 1, 1.5, 2, and 3), which was obtained for the first time by means of a new sol-gel approach. Analysis of neutron diffraction data revealed that the distribution of La/Sr and Ga/Al on the respective sites is random. 27Al and 71Ga solid state NMR enabled us to rationalize the local structure of the T sites in terms of nearest and next-nearest neighbors. This study provides a deep structural insight that can be helpful for the understanding of the functional properties and is a powerful strategy for the analysis of complex oxide systems

Published
2014

27. Observation of heteronuclear overhauser effects confirms the N-15-H-1 dipolar relaxation mechanism in a crystalline protein

Author

Giraud, N., Sein, J., Pintacuda, G., Bockmann, A., Lesage, A., Blackledge, M., Emsley, Lyndon, Laboratoire de Chimie - UMR5182 (LC), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de biologie et chimie des protéines [Lyon] (IBCP), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon)-Institut de Chimie du CNRS (INC)

Subjects
[SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology
Abstract

International audience; xxx

Published
2006
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31. Solution versus Solid-State Structure of Ytterbium Heterobimetallic Catalysts

Author

Di Bari L., Lelli M., Pintacuda G., Pescitelli G., Marchetti F., and Salvadori P.

Abstract

The solution structures of the ytterbium heterobimetallic complexes Na3[Yb((S)-BINOL)3] (1), K3[Yb((S)-BINOL)3] (2), and Li3[Yb((S)-BINOL)3] (3), belonging to a family of well-known enantioselective catalysts, are studied by means of NMR and circular dichroism (CD) in the UV and near-IR regions. The experimental NMR paramagnetic shifts were employed to obtain a refined solution structure of 1. NMR analysis demonstrated that 1, 2, and 3 have the same solution geometry but different magnetic susceptibility anisotropy D factors. By comparing XRD and NMR structures of 1, we demonstrate that, upon dissolution, this complex experiences a rearrangement from the crystalline C3 symmetry into the solution D3 symmetry. Remarkably, Yb is not bound to water in solution, and Ln-BINOL bonds are labile as demonstrated through EXSY. NIR-CD is confirmed especially sensitive to changes in the ytterbium coordination sphere.

Published
2003

33. Polymorphism and magnetic properties of Li2MSiO4 (M = Fe, Mn) cathode material

Author

Bini, M, Ferrari, S, Ferrara, C, Mozzati, M, Capsoni, D, Pell, A, Pintacuda, G, Canton, P, Mustarelli, P, Mozzati, MC, Pell, AJ, Bini, M, Ferrari, S, Ferrara, C, Mozzati, M, Capsoni, D, Pell, A, Pintacuda, G, Canton, P, Mustarelli, P, Mozzati, MC, and Pell, AJ

Abstract

Transition metal-based lithium orthosilicates (Li2MSiO4,M=Fe, Ni, Co, Mn) are gaining a wide interest as cathode materials for lithium-ion batteries. These materials present a very complex polymorphism that could affect their physical properties. In this work, we synthesized the Li2FeSiO4 and Li2MnSiO4 compounds by a sol-gel method at different temperatures. The samples were investigated by XRPD, TEM, 7Li MAS NMR, and magnetization measurements, in order to characterize the relationships between crystal structure and magnetic properties. High-quality 7Li MAS NMR spectra were used to determine the silicate structure, which can otherwise be hard to study due to possible mixtures of different polymorphs. The magnetization study revealed that the Neel temperature does not depend on the polymorph structure for both iron and manganese lithium orthosilicates

Published
2013

34. Local versus average structure in LaSrAl3O7: A NMR and DFT investigation

Author

Ferrara, C, Tealdi, C, Pedone, A, Menziani, M, Rossini, A, Pintacuda, G, Mustarelli, P, Menziani, MC, Rossini, AJ, Ferrara, C, Tealdi, C, Pedone, A, Menziani, M, Rossini, A, Pintacuda, G, Mustarelli, P, Menziani, MC, and Rossini, AJ

Abstract

LaSrAl3O7 belongs to the family of M 2T1(1)T2(2)O7 compounds with tetragonal melilite-like layered structure. In such compounds the local structure and properties may be very different from the average ones, mainly due to cationic disorder on the M site. In this work, solid-state 27Al NMR spectroscopy and periodic density functional theory calculations were used to highlight the differences between local and average order in the LaSrAl3O7 crystal. The 27Al isotropic chemical shifts and quadrupolar coupling constants were computed by employing the gauge including projector augmented wave (GIPAW) and PAW formalisms, respectively. An impressive linear relationship between the computed quadrupolar coupling constant CQ and the Al tetrahedra (T 1, T2) distortion was observed. In particular, our calculations showed that the distortion of the T2 environment is determined by the La/Sr speciation around the apical nonbridging oxygen

Published
2013

36. Ultra fast MAS solid-state NMR studies of protein-protein interactions in the bacterial replisome

Author

Felletti, M, Jehle, S, Wang, Y, Ozawa, Kiyoshi, Jergic, S, Otting, G, Emsley, L, Lesage, A, Dixon, N, Pintacuda, G, Felletti, M, Jehle, S, Wang, Y, Ozawa, Kiyoshi, Jergic, S, Otting, G, Emsley, L, Lesage, A, Dixon, N, and Pintacuda, G

Abstract

Replication of genomic DNA in bacteria involves multiple stable and transient interactions among protein subunits constituting the replisome. Here we show how ultra-fast magic angle spinning (MAS) solid-state NMR (ssNMR) and 1H-detection on either deutereted or fully protonated samples, can give new information about protein-protein interactions in the E. coli replisome. We focused on two fundamental interactions: the first one between the C-terminal domain of the single-stranded (ss) DNA binding protein and its own DNA-binding site, and the second one between the DNA polymerase III subunits a and s. SSB (a tetramer of 79 kDa) has a structurally well-defined ssDNA binding domain (OB-domain) and an intrinsically disordered C-terminal (Ct) domain. Its extreme Ct acidic motif is known to mediate the binding of SSB to different DNA processing enzymes and scaffold proteins. ssNMR provides, for the first time, residue-specific evidence for interaction, in multiple heterogeneous conformations, of SSB-Ct with its own ssDNA-binding site. In particular we compared spectra from the native protein and from a deletion mutant lacking the extreme Ct. This interaction acts as a switch that directs recruitment of SSB-binding proteins specifically to SSB only when it is bound to ssDNA. Moreover we investigated the interaction between the C-terminal domains of a (aCTS 22.5 kDa) and s (sC16 16 kDa). The structure of the complex is so far unknown. We used cell free protein synthesis to produce aCTS in the presence of sC16. We analyzed two different samples in which each the interacting partners is separately 2H,13C,15N labelled. The complete resonance assignment of the proteins in the complex opens the way to mapping the protein-protein contacts and to the determination of the overall structure

Published
2012

37. Studying amyloidogenic beta-2 microglobulin: the monomer, the oligomers and the fibrils

Author

Ricagno, S, Colombo, M, Grandori, R, Doglia, S, Pintacuda, G, Bellotti, V, Bolognesi, M, Bowie, J, Regan, L, Raleigh, D, Fetrow, J, Baum, J, Palmer III, AG, Matthews, B, GRANDORI, RITA, DOGLIA, SILVIA MARIA, Bolognesi, M., Ricagno, S, Colombo, M, Grandori, R, Doglia, S, Pintacuda, G, Bellotti, V, Bolognesi, M, Bowie, J, Regan, L, Raleigh, D, Fetrow, J, Baum, J, Palmer III, AG, Matthews, B, GRANDORI, RITA, DOGLIA, SILVIA MARIA, and Bolognesi, M.

Abstract

Amyloidosis has been found to be responsible for a growing number of misfolding disorders. Although several amyloid diseases are fatal and most are very severe, to date no effective treatment to any of the amyloid related diseases is available. In order to characterize the structural aspects of protein aggregation, the three main species present during amyloid aggregation have to be studied: the starting native fold, the oligomers and the mature amyloid fibrils. Beta-2 microglobulin (b2m) is an amylodogenic protein responsible for Dialysis Related Amyloidosis a disorder resulting in severe movement impairment. Aiming to understand the structural determinants of b2m aggregation propensity, we have characterised the role of the DE loop in the monomeric b2m. Mutations in such loop revealed that modifying the geometry of the DE loop has global effects on b2m: such mutations affect b2m folding, fold stability, structure, amyloidogenic propensity and dynamics under native and denaturating conditions. Such effects have been studied by several techniques such as X-ray crystallography, circular dichroism, intrinsic fluorescence, mass spectrometry and infrared spectroscopy. In order to shed light on the structural details of b2m aggregation, a strategy to form artificial oligomers amenable for crystallographic studies have been designed and it will be shown together with the structures of two artificial oligomers and their propensity to form amyloid fibrils. Finally ssNMR experiments on double and triple labelled samples of crystalline and fibrillar b2m will be presented. In particular spectra of crystalline and aggregated b2m reveal that the most of b2m is structured in amyloid fibrils

Published
2012

43. Structural Characterization of the EtOH–TiCl4–MgCl2Ziegler–Natta Precatalyst

Author

D’Anna, V., Norsic, S., Gajan, D., Sanders, K., Pell, A. J., Lesage, A., Monteil, V., Copéret, C., Pintacuda, G., and Sautet, P.

Abstract

The Ziegler–Natta polymerization is one major example of application of catalysis in industry. Since the first discovery of Ziegler and Natta, several modifications of the catalyst have been developed, in order to improve its performance. Nowadays, a typical Ziegler–Natta catalyst for polyethylene synthesis consists of a precatalyst, composed of TiCl4supported on MgCl2in the presence of a Lewis base, activated by organoaluminum. The atomic-scale characterization of the Ziegler–Natta catalyst is crucial for further improvement of the catalyst. Here, the precatalyst TiCl4–MgCl2with EtOH as internal Lewis base is characterized combining solid-state NMR spectroscopy and periodic density functional theory calculations. From total energy and NMR spectra, eight surface species were proposed showing EtO–ligands on the Ti and EtOH/EtO–on the surface Mg species. These species lead to a complete interpretation of the NMR two-dimensional spectra. Hence a detailed molecular scale description of the precatalyst was obtained.

Published
2016
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45. Illuminating xist

Author

Heather Coker, Moindrot, B., Pintacuda, G., and Brockdorff, N.

Subjects
General Biochemistry, Genetics and Molecular Biology
Abstract

The Central Dogma proposed that RNA, encoded by DNA in the genome, acts as the template used by cells for protein production. The simplicity of RNA as a discrete mediator of information has subsequently been challenged by the discovery of non-protein-coding RNAs. Understanding of this intricate new field has been fuelled by the development of new research techniques. In this article, we consider how recent advances in microscopy have added to our current understanding of the non-coding RNA Xist (X-inactive specific transcript).

46. A Pooled shRNA Screen Identifies Rbm15, Spen, and Wtap as Factors Required for Xist RNA-Mediated Silencing

Author

Moindrot B, Cerase A, Coker H, Masui O, Grijzenhout A, Pintacuda G, Schermelleh L, Tatyana Nesterova, and Brockdorff N

Subjects
Xist, Cell Nucleus, Rbm15, Active Transport, Cell Nucleus, Nuclear Proteins, RNA-Binding Proteins, Cell Cycle Proteins, Article, WTAP, Protein Structure, Tertiary, DNA-Binding Proteins, Mice, lcsh:Biology (General), X chromosome inactivation, Xist, Spen, WTAP, Rbm15, Spen, Animals, RNA, Long Noncoding, Gene Silencing, RNA Splicing Factors, X chromosome inactivation, Carrier Proteins, lcsh:QH301-705.5, Cells, Cultured, Embryonic Stem Cells, Protein Binding
Abstract

Summary X-chromosome inactivation is the process that evolved in mammals to equalize levels of X-linked gene expression in XX females relative to XY males. Silencing of a single X chromosome in female cells is mediated by the non-coding RNA Xist. Although progress has been made toward identifying factors that function in the maintenance of X inactivation, the primary silencing factors are largely undefined. We developed an shRNA screening strategy to produce a ranked list of candidate primary silencing factors. Validation experiments performed on several of the top hits identified the SPOC domain RNA binding proteins Rbm15 and Spen and Wtap, a component of the m6A RNA methyltransferase complex, as playing an important role in the establishment of Xist-mediated silencing. Localization analysis using super-resolution 3D-SIM microscopy demonstrates that these factors co-localize with Xist RNA within the nuclear matrix subcompartment, consistent with a direct interaction., Graphical Abstract, Highlights • An shRNA screen identifies factors implicated in chromosome silencing by Xist RNA • Rbm15, Wtap, and Spen are required for Xist-mediated silencing • Rbm15 is important for efficient deposition of H3K27me3 on the inactive chromosome • Rbm15, Wtap, and Spen co-localize with Xist RNA in perichromatin spaces, To identify primary silencing factors implicated in X-chromosome inactivation, Moindrot et al. set up a pooled shRNA genetic screen. The RNA-binding proteins Rbm15 and Spen, together with Wtap, a subunit of the RNA methylation complex, were identified as important factors required for Xist-mediated silencing.

49. To Which Extent Is Paramagnetic Solid-State NMR Able To Address Polymorphism in Complex Transition-Metal Oxides?

Author

Stefania Ferrari, Piercarlo Mustarelli, Doretta Capsoni, Guido Pintacuda, Marcella Bini, Chiara Ferrara, Dept Chem, University of Pavia, Biological Solid-State NMR Methods - Méthodes de RMN à l'état solide en biologie, Institut des Sciences Analytiques (ISA), Institut de Chimie du CNRS (INC)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Dipartimento di Scienza dei Materiali = Department of Materials Science [Milano-Bicocca], Università degli Studi di Milano-Bicocca [Milano] (UNIMIB), INSTM, Ferrara, C, Ferrari, S, Bini, M, Capsoni, D, Pintacuda, G, and Mustarelli, P

Subjects
Diffraction, Materials science, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Cathode, Spectral line, 0104 chemical sciences, 3. Good health, law.invention, Paramagnetism, Solid-state nuclear magnetic resonance, Polymorphism (materials science), Transition metal, law, Chemical physics, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, General Materials Science, Materials Science (all), Physical and Theoretical Chemistry, 0210 nano-technology, Adiabatic process, ComputingMilieux_MISCELLANEOUS
Abstract

A detailed characterization of the polymorphs constituting cathode materials, both before and after cell cycling, is mandatory to develop more stable and powerful lithium batteries. In many cases, e.g., for transition metal lithium silicates, standard diffraction techniques cannot give a clear-cut response. Here we show that broadband adiabatic fast MAS NMR can give unique information in the case of model Li2(Mn,Fe)SiO4 high-capacity cathode materials. By coupling 7Li and 29Si 1D and 2D spectra, we are able to address polymorphs speciation also in the mixed Mn/Fe compositions, which is a nearly impossible task for X-rays and neutrons diffraction. We finally discuss the conditions under which this approach is useful when applied to rare nuclei such as 29Si.

Published
2018
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50. Target highlights from the first post-PSI CASP experiment (CASP12, May-August 2016)

Author

Shabir Najmudin, Johan C. Hill, Guido Pintacuda, Kinlin L. Chao, John Moult, Arnaud Baslé, T.H. Nguyen, Kaspars Tars, Harry J. Gilbert, Krzysztof Fidelis, Christopher S. Hayes, Marco Nardini, Reinhard Albrecht, Mark J. van Raaij, Valentina Nardone, Roman I. Koning, Celia W. Goulding, Pedro Bule, A.K. Singh, Nicole Zitzmann, Andrzej Joachimiak, Osnat Herzberg, Leila Lo Leggio, Carlos M. G. A. Fontes, Eric J. Sundberg, Pietro Roversi, Didier Ndeh, Andriy Kryshtafovych, Amir Shimon, Gert Wieland Kohring, Folmer Fredslund, Alessandro T. Caputo, Ana Luísa Carvalho, Marco Mangiagalli, Karolina Michalska, Sandra Postel, Marcus D. Hartmann, Torsten Schwede, Ron Diskin, Genome Center [UC Davis], University of California [Davis] (UC Davis), University of California-University of California, Abteilung Membranbiochemie [Martinsried], Max-Planck-Institut für Biochemie (MPIB), Max-Planck-Gesellschaft-Max-Planck-Gesellschaft, Institute for Cell and Molecular Biosciences, Newcastle University [Newcastle], Interdisciplinary Centre of Research in Animal Health, Faculdade de Medicina Veterinária, Pólo Universitário do Alto da Ajuda, Universidade de Lisboa, Oxford Glycobiol Inst, Dept Biochem, University of Oxford [Oxford], Unidade de Ciencias Biomoleculares Aplicadas (UCIBIO), Requimte, Departamento de Química (DQ), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade do Porto-Departamento de Química (DQ), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade do Porto, Dept Mol Cellular & Dev Biol, University of California [Santa Barbara] (UCSB), Structural Biology Center, Biosciences Division, Universität des Saarlandes [Saarbrücken], Department of Chemistry, University of Copenhagenn, Department of Cell Biology and Molecular Genetics, University of Maryland [College Park], University of Maryland System-University of Maryland System, Department of Biomolecular Sciences and Biotechnology, University of Milano, Biological Solid-State NMR Methods - Méthodes de RMN à l'état solide en biologie, Institut des Sciences Analytiques (ISA), Institut de Chimie du CNRS (INC)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Biomedical Research & Study Centre, Department of Biochemistry [Oxford], Biozentrum [Basel, Suisse], University of Basel (Unibas), Kryshtafovych, A, Albrecht, R, Baslé, A, Bule, P, Caputo, A, Carvalho, A, Chao, K, Diskin, R, Fidelis, K, Fontes, C, Fredslund, F, Gilbert, H, Goulding, C, Hartmann, M, Hayes, C, Herzberg, O, Hill, J, Joachimiak, A, Kohring, G, Koning, R, Lo Leggio, L, Mangiagalli, M, Michalska, K, Moult, J, Najmudin, S, Nardini, M, Nardone, V, Ndeh, D, Nguyen, T, Pintacuda, G, Postel, S, Van Raaij, M, Roversi, P, Shimon, A, Singh, A, Sundberg, E, Tars, K, Zitzmann, N, and Schwede, T

Subjects
0301 basic medicine, Models, Molecular, Protein Folding, Protein Conformation, Bioinformatics, FIS/07 - FISICA APPLICATA (A BENI CULTURALI, AMBIENTALI, BIOLOGIA E MEDICINA), Computational biology, computer.software_genre, Crystallography, X-Ray, Biochemistry, Article, Mathematical Sciences, 03 medical and health sciences, Structural Biology, Models, Information and Computing Sciences, [CHIM]Chemical Sciences, Animals, Humans, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, CASP, Molecular Biology, X-ray crystallography, Physics, Crystallography, Bacteria, Proteins, Computational Biology, Molecular, Protein structure prediction, Biological Sciences, BIO/10 - BIOCHIMICA, NMR, protein structure prediction, 030104 developmental biology, Biological significance, X-Ray, Data mining, computer, Software
Abstract

International audience; The functional and biological significance of the selected CASP12 targets are described by the authors of the structures. The crystallographers discuss the most interesting structural features of the target proteins and assess whether these features were correctly reproduced in the predictions submitted to the CASP12 experiment.

Published
2018
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