58 research outputs found
Aimer ses cheveux, s’aimer : une proposition radicale de Josépha Labbé. Femmes afro-caribéennes et esthétique capillaire dans le Paris des années 70
No full textL’auteure propose une analyse critique de la démarche de la Martiniquaise Josépha Labbé-Jouffret dans le Paris des années 70, soulignant le caractère radical de son approche auprès des femmes antillaises d’alors. En proposant aux femmes de tout simplement aimer leur chevelure et de la porter naturelle, Josépha Labbé-Jouffret leur offrait une plateforme politique, visant à entamer une libération du poids du passé esclavagiste. Sa méthode s’ancrait dans l’humus antillais, et la pensée théorique de l’auteure s’appuie sur deux aphorismes : Tout Moun Sé Moun et Sé Dèyè Pawol Ki Ni Pawol. En effet, la mission de Josépha Labbé-Jouffret consistait à rétablir ses clientes dans leur dignité de moun par une démarche souple qui les accompagnait dans leur évolution.The author offers a critical analysis of the Martinican, Josépha Labbé-Jouffret’s approach, in the Paris of the 1970s, and underlines the radical nature of her work for French Caribbean women at the time. By simply offering women the opportunity to love their hair and to keep it natural, Josépha Labbé-Jouffret gave them a political platform, which aimed at freeing them from the weight of the slave past. Her method was rooted in the Antillean humus, and the theoretical thought of the author relies on two aphorisms: Tout Moun Sé Moun and Sé Dèyè Pawol Ki Ni Pawol. Indeed, Josépha Labbé-Jouffret’s mission was to establish her clients in their dignity as moun through a method that accompanied them in their evolution.La autora ofrece un análisis crítico del planteamiento de la martiniquesa Josépha Labbé-Jouffret en el París de los años setenta, destacando la radicalidad de su acercamiento a las mujeres antillanas de la época. Al proponer a las mujeres que simplemente amen su cabello y lo lleven con naturalidad, Josépha Labbé-Jouffret les ofrecía una plataforma política para empezar a liberarse del peso del pasado esclavista. Su método estaba arraigado en el humus antillano, y su pensamiento teórico se basaba en dos aforismos : Tout Moun Sé Moun y Sé Dèyè Pawol Ki Ni Pawol. En efecto, la misión de Josépha Labbé-Jouffret era devolver a sus clientes su dignidad de moun mediante un enfoque flexible que les acompañara en su evolución
Recent advances in proteotyping pathogens and environmental microorganisms by tandem mass spectrometry
No full textInternational audienceQuestion. Tandem mass spectrometry-based proteotyping of microorganisms has key advantages over other approaches. Due to a greater number of signals recorded, the methodology allows the identification of microorganisms at highly resolved taxonomic levels and can manage complex samples (Grenga et al., 2019). Here, we document its application to pathogens and environmental microorganisms, test its sensitivity and explore the possibility of high-throughput for culturomics. Methods. Peptides generated with trypsin were analyzed by means of several high resolution instruments (LTQ-Orbitrap XL, Q-Exactive HF, Exploris480 mass spectrometers) operated in data-dependent acquisition mode. MS/MS spectra were identified using a cascade of searches conceived for maximizing metaproteomics results against a giant database comprising all sequenced genomes to date. The taxonomy of the microorganisms was established on the basis of the taxon-specific peptides and the taxon-assigned MS/MS spectra. Results. The distribution of assigned Taxon-Spectrum Matches according to the taxa present in the database was modeled, leading to the discovery of the “Phylopeptidomic” signature (Pible et al., 2020). This signature makes it possible to quantify the biomass of each microorganism present in a mixture. Sample preparation for proteotyping has been improved to analyze hundreds of isolates (Hayoun et al., 2019 & 2020), making this methodology truly amenable to culturomics. The proteotyping approach can be applied to clinical pathogens as well as poorly documented environmental microorganisms, whatever the branch of the Tree of Life. We further documented the methodology showing that the sensitivity of the method is 10E4 bacterial cells required for typing at the species level. Finally, a multiplexing methodology was developed to be able to analyze dozens of isolates per analytical run, and identify their potential antibiotic resistance at the same time. Conclusions. Overall, tandem mass spectrometry-based proteotyping is an interesting application of proteomics for rapid microbiological taxonomy. The taxonomic identification without a priori and the characterization of resistance to antibiotics pave the way for a new revolution in the clinical microbiology laboratory.References.Hayoun K, Gaillard JC, Pible O, Alpha-Bazin B, Armengaud J (2020) J. Proteomics 226:103887. Gouveia D, Grenga L, Pible O, Armengaud J (2020) Environ Microbiol. 22(8):2996-3004. Pible O, Allain F, Jouffret V, Culotta K, Miotello G, Armengaud J (2020) Microbiome 8:30. Hayoun K, Gouveia D, Grenga L, Pible O, Armengaud J, Alpha-Bazin B (2019) Frontiers in Microbiol10:1985. Grenga L, Pible O, Armengaud J (2019) Clinical Mass Spectrometry 14:9-17
Synthèse hydrothermale d'uranyle-vanadates et d'uranyle-phosphates (influence des amines et dimensionnalité des arrangements inorganiques)
No full textLa chimie du solide des composes hybrides organiques inorganiques contenant l uranium a été récemment enrichie par une multiplication de publications concernant des matériaux bi ou tri dimensionnels. Ce travail porte sur la synthèse hydrothermale de composés des systèmes uranyle-vanadate-amines et uranyle-phosphate-amines. La résolution des structures de ces composés s est faite par diffraction des rayons X sur monocristal. Leur stabilité thermique a aussi été étudiée. Suivant le pH de la solution, et l amine utilisée, différentes familles de composés apparaissent. A pH basique, les composés obtenus sont bidimensionnels avec des couches correspondant à celles des phases naturelles, à savoir couches de type carnotite pour les uranyle-vanadates ou de type autunite pour les uranyle-phosphates. A pH acide, des composés à charpente tridimensionnelle sont stabilisés par la présence des amines. Les arrangements résultent de couches uranyle-vanadate ou uranyle-phosphate de type uranophane reliées par des piliers uranyle. Ces arrangements présentent différents rapports U/V ou U/P selon l isomérie géométrique de la couche uranophane. L identification de nouveaux isomères géométriques a généré une classification de ces isomères qui permet une comparaison simple et la compréhension de leur formation. Enfin, l utilisation de l éthylène diamine dans le système uranyle-phosphate permet la réduction in situ de l uranium (VI) en uranium (IV) et la formation d un phosphate d uranium (IV) où les couches uranium-phosphate alternent avec des couches d éthylène diamine diprotonnéeSolid state chemistry of hybrid organic-inorganic compounds containing uranium has been enriched recently by a multiplication of papers dealing with two and three dimensional inorganic materials. This work deals with hydrothermal synthesis of compounds in the uranyl-phosphate-amine and uranyl-vanadate-amine systems. Determination of their structure was done by X-ray diffraction on single crystals. Their thermal stability was also studied. According to the pH of the initial solutions, and nature of the amine used, different families of compounds appear. With a basic pH, the obtained compounds are two dimensional with the layers corresponding to those found in naturally occurring phases, such as carnotite type layer for the uranyl-vanadate system and autunite for the uranyl-phosphate system. With an acidic pH, compounds with three dimensional frameworks are stabilized by the presence of the amines. The frameworks result from uranophane type uranyl-vanadate or uranyl-phosphate layers connected by uranyl pillars. They display different U/V or U/P ratios depending on the geometric isomer of the uranophane layer. Identification of new geometric isomers has led to a simple classification of the isomers which helps to their comparison and to the understanding of their formation. Finally, using ethylene diamine in the uranyl-phosphate system reduces in situ uranium (VI) into uranium (IV) and forms a uranium (IV) phosphate in which the uranium-phosphate layers alternate with diprotonated ethylene diamine layers.LILLE1-Bib. Electronique (590099901) / SudocSudocFranceF
Recent advances in proteotyping pathogens and environmental microorganisms by tandem mass spectrometry
No full textInternational audienceQuestion. Tandem mass spectrometry-based proteotyping of microorganisms has key advantages over other approaches. Due to a greater number of signals recorded, the methodology allows the identification of microorganisms at highly resolved taxonomic levels and can manage complex samples (Grenga et al., 2019). Here, we document its application to pathogens and environmental microorganisms, test its sensitivity and explore the possibility of high-throughput for culturomics. Methods. Peptides generated with trypsin were analyzed by means of several high resolution instruments (LTQ-Orbitrap XL, Q-Exactive HF, Exploris480 mass spectrometers) operated in data-dependent acquisition mode. MS/MS spectra were identified using a cascade of searches conceived for maximizing metaproteomics results against a giant database comprising all sequenced genomes to date. The taxonomy of the microorganisms was established on the basis of the taxon-specific peptides and the taxon-assigned MS/MS spectra. Results. The distribution of assigned Taxon-Spectrum Matches according to the taxa present in the database was modeled, leading to the discovery of the “Phylopeptidomic” signature (Pible et al., 2020). This signature makes it possible to quantify the biomass of each microorganism present in a mixture. Sample preparation for proteotyping has been improved to analyze hundreds of isolates (Hayoun et al., 2019 & 2020), making this methodology truly amenable to culturomics. The proteotyping approach can be applied to clinical pathogens as well as poorly documented environmental microorganisms, whatever the branch of the Tree of Life. We further documented the methodology showing that the sensitivity of the method is 10E4 bacterial cells required for typing at the species level. Finally, a multiplexing methodology was developed to be able to analyze dozens of isolates per analytical run, and identify their potential antibiotic resistance at the same time. Conclusions. Overall, tandem mass spectrometry-based proteotyping is an interesting application of proteomics for rapid microbiological taxonomy. The taxonomic identification without a priori and the characterization of resistance to antibiotics pave the way for a new revolution in the clinical microbiology laboratory.References.Hayoun K, Gaillard JC, Pible O, Alpha-Bazin B, Armengaud J (2020) J. Proteomics 226:103887. Gouveia D, Grenga L, Pible O, Armengaud J (2020) Environ Microbiol. 22(8):2996-3004. Pible O, Allain F, Jouffret V, Culotta K, Miotello G, Armengaud J (2020) Microbiome 8:30. Hayoun K, Gouveia D, Grenga L, Pible O, Armengaud J, Alpha-Bazin B (2019) Frontiers in Microbiol10:1985. Grenga L, Pible O, Armengaud J (2019) Clinical Mass Spectrometry 14:9-17
Study of the high-pressure structure of fluoroperovskite : the lamellar postperovskite.
No full textInternational audienc
Démêler les fonctions du microbiote par métaprotéomique
No full textInternational audienceLes écosystèmes microbiens jouent un rôle majeur pour les cycles élémentaires dans la nature, le développement des plantes et la santé des animaux. Comment les microorganismes interagissent entre eux, avec leurs hôtes, et avec leur environnement sont des questions abordées par la métaprotéomique. L’étude des protéines de ces échantillons particulièrement complexes permet d’obtenir quatre types de réponses : 1) identification des taxa présents, 2) quantification des biomasses de ces organismes, 3) identification des protéines de ces taxa et leur fonctionnement, et 4) représentation fonctionnelle globale du système biologique. Afin de mieux comprendre le fonctionnement des microbiotes, la question de la quantification des biomasses est essentielle. Le concept récemment développé de « phylopeptidomique » permet une quantification plus précise de la biomasse protéique des taxons identifiés [1], mettant en évidence une nouvelle dimension à partir des données du microbiome, et améliore le protéotypage des taxons environnementaux [2-4]. Les défis en terme de spectrométrie de masse, d’interprétation et fouille des résultats seront abordés. Plusieurs exemples récents seront présentés [5-8] ainsi que notre vision de la métaprotéomique en tant qu’outil de diagnostic [9].Références bibliographiques:1. Pible O, Allain F, Jouffret V, Culotta K, Miotello G, Armengaud J (2020) Estimating relative biomasses of organisms in microbiota using “phylopeptidomics”. Microbiome 8:30.2. Hayoun K, Gaillard JC, Pible O, Alpha-Bazin B, Armengaud J (2020) High-throughput proteotyping of bacterial isolates by double barrel chromatography-tandem mass spectrometry based on microplate paramagnetic beads and phylopeptidomics. J. Proteomics 226:103887. 3. Hayoun K, Pible O, Petit P, Allain F, Jouffret V, Culotta K, Rivasseau C, Armengaud J, Alpha-Bazin B (2020) Proteotyping Environmental Microorganisms by Phylopeptidomics: Case Study Screening Water from a Radioactive Material Storage Pool. Microorganisms 8(10):E1525.4. Lozano C, Kielbasa M, Gaillard JC, Miotello G, Pible O, Armengaud J (2022) Identification and characterization of marine microorganisms by tandem mass spectrometry proteotyping. Microorganisms 10(4):719. doi: 10.3390/microorganisms10040719.5. Gouveia D, Pible O, Culotta K, Jouffret V, Geffard O, Chaumot A, Degli-Esposti D, Armengaud J (2020) Combining proteogenomics and metaproteomics for deep taxonomic and functional characterization of microbiomes from a non-sequenced host. NPJ Biofilms Microbiomes 5:6(1):23.6. Bourdin V, Charlier P, Crevat S, Slimani L, Chaussain C, Kielbasa M, Pible O, Armengaud J (2023) Deep paleoproteotyping and microtomography revealed no heart defect nor traces of embalming in the cardiac relics of Blessed Pauline Jaricot. International Journal of Molecular Sciences, 24(3):3011. doi: 10.3390/ijms24033011.7. Grenga L, Pible O, Miotello G, Culotta K, Ruat S, Roncato MA, Gas F, Bellanger L, Claret PG, Dunyach-Remy C, Laureillard D, Sotto A, Lavigne JP, Armengaud J (2022) Taxonomical and functional changes in COVID-19 faecal microbiome could be related to SARS-CoV-2 faecal load. Env Microbiol. 24(9):4299-4316. doi: 10.1111/1462-2920.16028.8. Hardouin P, Pible O, Marchandin H, Culotta K, Armengaud J, Chiron R, Grenga L (2022) Quick and wide-range taxonomical repertoire establishment of the cystic fibrosis lung microbiota by tandem mass spectrometry on sputum samples. Frontiers in Microbiology 13:975883. doi: 10.3389/fmicb.2022.975883.9. Armengaud J (2023) Metaproteomics to understand how microbiota function: the crystal ball predicts a promising future. Env Microbiol 25(1):115-125. doi: 10.1111/1462-2920.16238
TDP1 mutation causing SCAN1 neurodegenerative syndrome hampers the repair of transcriptional DNA double-strand breaks
No full textTDP1 removes transcription-blocking topoisomerase I cleavage complexes (TOP1ccs), and its inactivating H493R mutation causes the neurodegenerative syndrome SCAN1. However, the molecular mechanism underlying the SCAN1 phenotype is unclear. Here, we generate human SCAN1 cell models using CRISPR-Cas9 and show that they accumulate TOP1ccs along with changes in gene expression and genomic distribution of R-loops. SCAN1 cells also accumulate transcriptional DNA double-strand breaks (DSBs) specifically in the G1 cell population due to increased DSB formation and lack of repair, both resulting from abortive removal of transcription-blocking TOP1ccs. Deficient TDP1 activity causes increased DSB production, and the presence of mutated TDP1 protein hampers DSB repair by a TDP2-dependent backup pathway. This study provides powerful models to study TDP1 functions under physiological and pathological conditions and unravels that a gain of function of the mutated TDP1 protein, which prevents DSB repair, rather than a loss of TDP1 activity itself, could contribute to SCAN1 pathogenesis
Synthesis, crystal structure, spectroscopic study and Hirshfeld surface analysis of [Ni(C6H8N2)3]Cl2.2(H2O) (1)
No full textInternational audienceThe title compound, [Ni(C 6 H 8 N 2 ) 3 ]Cl 2 .2(H 2 O), was synthesized by slow evaporation method at room tem- perature. The structural study by X–ray diffraction indicate that this compound crystallize in the tri- clinic system, P-1 space group with a = 10.222(2) ˚A, b = 10.757(2) ˚A, c = 11.441(3) ˚A, α= 114.30(4) °, β= 99.43(3) °and γ= 93.01(3) °. The structure is formed by the cation [Ni(C 6 H 8 N 2 ) 3 ] 2 + , tow chloride an- ions and two molecules water of crystallization. The nickel (II) atom is coordinated to six nitrogen donors from three neutral 2-AMP ligands, adopting a slightly distorted octahedral geometry. The crystal struc- ture is stabilized by strong hydrogen bonds of N–H…Cl, O–H…Cl, C–H…Cl and π–πinteractions to ob- tained three–dimensional network. The newly prepared compound was characterized by XRD, Infrared, UV–Vis spectroscopy and Hirshfeld surface (3D-HS) analysis. Vibrational analysis of the compound was realized by infrared spectroscopy. The optical properties of the crystal were studied using optical absorp- tion UV–visible spectroscopy which confirmed the semiconducting properties by revealing a direct optical band. Hirshfeld Surface projections and Fingerprint plots were elucidated the relative contribution of the H…Cl, C…H, C…C, C…N, H…O intermolecular contacts in the crystal
Synthesis and characterization of a hybrid material (C10H28N4) [CoCl4]2 using Hirshfeld surface, vibrational and optical spectroscopy, DFT calculations and biological activities
No full textInternational audienceThe preparation and structural characterization of a new complex compound (C10H28N4) [CoCl4]2 (abbreviated BAPCO) were reported. The crystal was grown by the room temperature slow evaporation method and characterized by single crystal X-Ray diffraction. The functional groups present in BAPCO were characterized by several techniques such as FT-IR, UV-Vis absorption and photoluminescence spectroscopy, thermal measurement, Hirshfeld surface analysis and DFT investigation. The title compound crystallizes in the P21/n space group of the monoclinic system with the following cell parameters: a = 18.5765(11) Å, b = 7.1390(4) Å, c = 18.6346(11) Å, β = 110.858(3)°, Z = 4 and V = 2309.3(2) Å3. The structure consists of an alternation along the a-axis of organic layers formed by [C10H28N4]4+cations and inorganic layers built up of isolated tetrahedral [CoCl4]2−. The crystal cohesion is ensured by a network of Nsingle bondH … Cl and Csingle bondH … Cl hydrogen bonds. Vibrational and optical properties were explored by means of experimental techniques along with DFT and TDDFT calculations. Furthermore, frontier molecular orbital analysis (HOMO-LUMO) was accomplished to understand the chemical stability of BAPCO, and the activation of thermodynamic parameters are calculated. Good agreement was found between theoretical and experimental results. The bioassay results showed that the structure exhibits significant antibacterial activity
Surface pre-coating of talc particles by carboxyl methyl cellulose adsorption : study of adsorption and consequences on surface properties and settling rate
No full textThis paper investigates the adsorption of different sized carboxyl methyl cellulose (CMC) onto talc particles (adsorption isotherm, adsorption reversibility), its consequences on the particles properties (electrophoretic mobility and surface wetting) and its effect on their
dispersion (settling coefficient). Throughout the paper, the properties of talc particles dispersed in CMC solution are compared to CMC pre-coated talc particles: talc particles dried in a solution of CMC before their redispersion. The adsorption of CMC onto talc was
quantified at around 0.4 mg of CMC per m2 of talc and was seen to be irreversible on washing the talc particles with distilled water. When characterising talc surface properties, it was found that CMC adsorption leads to an increase of the negative surface charge and to an increase of the wettability. The settling velocity of CMC pre-coated talc particles in water can be around
50 % lower than that of the initial talc particles. The pre-coating of talc particles by CMC is then assumed to increase their stabilization : particle aggregation is hindered by adsorbed CMC layer inducing electrosteric repulsion between the talc particles. The technique of talc
pre-coating with CMC makes the talc dispersion easier and could open interesting perspectives in engineering processes using talc dispersions
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