Rafael Bermeo thesis defense on June, 18th 2021
Rafael Bermeo will defend his thesis on June 18th, 2021, which he performed under the supervision of Dr. Annabelle Barrot (CNRS Research Director at Cermav – UPR5301) and which is entitled “Design, synthesis and evaluation of antagonists towards BC2L-C ”. Click on the title for more information.
Morphological and Structural Aspects of α-Glucan Particles from Electron Microscopy Observations
The book “Enzymology of Complex Alpha-Glucans”, edited by Felix Nitschke, will be published in July 2021. The first of the 11 chapters is devoted to the morphological and structural study of starch granules and glycogen using electron microscopy various techniques.
Fur4Sustain training school on ‘Polymer Characterization’
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We are pleased to announce the first FUR4Sustain training school on “Characterization of polymers” with the intervention of Dr Laurent Heux and Jean-Luc Putaux. The event will be held at the Université Côte d’Azur in Nice (FR) from June 14 to 17 (face-to-face or virtual via zoom). Click on the title for more information.
Lukáš Gajdoš thesis defense on May, 20th 2021
Lukáš Gajdoš from Cermav-UPR5301 and Institut Laue-Langevin in Grenoble will defend his thesis entitled: “Neutron diffraction for deciphering lectin-glycan interactions involved in bacterial infection”. Click on the title for more information.
Temperature-triggered formation of a cellulose II nanocrystal network through regioselective derivatization
We took advantage of the antiparallel arrangement of the chains within the cellulose II nanocrystals to graft gold nanoparticles or thermosensitive polymer chains to both ends of these rods. In the latter case, a temperature variation induces the formation of a network with a gel-like behaviour by the end-to-end association of the rods.
Visualisation of hydrogen atoms in a perdeuterated lectin-fucose complex reveals key details of protein-carbohydrate interactions
The pathogenic bacteria attach themselves to the cells which they attack thanks to the sugars present on their membrane. A crucial mechanism to study, because it would help to treat these infections without reinforcing the resistance of the bacteria. To do this, researchers from CERMAV (CNRS), the Laue-Langevin Institute (ILL) and CEITEC (Masaryk University, Czech Republic) have modified a sugar so that it responds to neutron crystallography, a technique that reveals how bacteria cling to sugars. This work, published in the journal Structure, could extend to more complex sugars to better understand different biological phenomena and propose new anti-infectious strategies. Caption: Fucose molecule in the lectin binding site. The blue grid represents the density determined by x-rays and the green grid the density determined by the neutrons around the fucose and the amino acids of the lectin. Hydrogen atoms (here isotope deuterium) are represented by yellow balls. The continuity of the green grid between the fucose and the amino acids allows a direct view of the hydrogen bonds. © L. Gajdos. / Click on the title for more information.
Replay: Serge Perez’s seminar: “Starch: An iconoclast view on amylopectin”, presented at the 7th “Special Infogest Webinar on Food Digestion”
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Small Angle Neutron Scattering Shows Nanoscale PMMA Distribution in Transparent Wood Biocomposites
« Transparent wood » can be prepared by filling the pores with resine, but how are the resine distributed. By small angle neutron scattering on samples with varyous the isotope composition of the resine we showed unambiguouslly the nanomeric ditribution of resine in the interstices of microfibrils in the cell wall. Click on the title to access more information.
Crystal and molecular structure of V-amylose complexed with ibuprofen
We have published an article in Carbohydrate Polymers about the structure of an inclusion compound prepared by crystallizing amylose in the presence of ibuprofen, a well-known anti-inflammatory drug. Using data from solid-state NMR, and electron and X-ray diffraction, we have proposed a molecular model allowing to locate the ibuprofen guest molecules in the lattice of amylose helices. Click on the title for more information.
Process-dependent nanostructures of regenerated cellulose fibres revealed by small angle neutron scattering
The nanostructure and properties of regenerated cellulose fibers depends on the spinning process. We revealed different structures by collecting small angle neutron scattering data on a series of fibers exposed to heavy water vapours. Click on the title for more information.
Daniel Marquez-Martin thesis defense on March, 16th 2021
Daniel Marquez-Martin from Cermav-UPR5301 and SyMMES- UMR5819 laboratories will defend his thesis entitled: “Versatile biosensor for deciphering glycoenzymatic activities”. Click on the title for more information.
Breakdown and buildup mechanisms of cellulose nanocrystal suspensions under shear and upon relaxation probed by SAXS and SALS
In this study supervised by Frédéric Pignon (LRP, Grenoble), the complementary use of small-angle scattering of light (structure at the microscopic scale) and X-rays (structure at the nano scale) allowed us to revisit the mechanism of orientation under flow of suspensions of cellulose nanocrystals in the liquid-crystal phase. Click on the title for more information.
Interview
Redouane Borsali, CNRS Research Director at Cermav, was interviewed in the latest newsletter from the North-East Asia CNRS office (on February 2021) about his research activities and the launch of an international research project with National Taiwan University (NTU) entitled “New ultra-nanostructured and stretchable biomaterials for
design of bio-electronic devices ”. Click on the title for more information.
INFOGEST Webinar Series on Food Digestion: ‘Starch: An iconoclast view on amylopectin’
Mar 15, 2021 11:00 AM in Dublin.
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Optimized Reducing-End Labeling of Cellulose Nanocrystals: Implication for the Structure of Microfibril Bundles in Plant Cell Walls
Using a new method, we have optimized the regioselective grafting of gold nanoparticles at the reducing end of cellulose nanocrystals. The hybrid nanoparticles produced are interesting for designing materials with innovative optical properties and reveal information on the in vivo organization of the microfibrils they originate from. Click on the title for more information.
Francois Bonnardel’s thesis defense on February, 8th 2021
Such thesis is entitled “Bioinformatic study of lectins: new classification and prediction in genomes” and is co-directed by Dr. Anne Imberty (Cermav) and Dr/Prof. Frédérique Lisacek (Swiss Institute of Bioinformatics). Click on the title for more information.
Find our work in the CNRS 2020 chemistry news booklet
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Marie Carriere’ s thesis defense on January 25th, 2021
Such thesis is entitled “Design, characterization and application of glyconanoparticles in (bio) electrochemistry”. It is executed in collaboration with the Département de Chimie Moléculaire (DCM), and the CEntre de Recherches sur les MAcromolécules Végétales (CERMAV) (co-supervised by Redouane BORSALI -Director of Research at CNRS). Click on the title for more information.
Bottom-up Construction of Xylan Nanocrystals in Dimethyl Sulfoxide
In collaboration with Aalto University and VTT (Finland), we developed a new hemicellulose-based nanocrystal composed of crystalline complex of xylan and dimethyl sulfoxide. The detailed structural characterization revealed that the xylan molecules are packed in the nanocrystals with a two-fold helical conformation which is different from the three-fold helical conformation found in the pure xylan crystal. The morphology of nanocrystals was found to be adjustable through changing the crystallization conditions. This work will serve as a starting point to understand the controlled assembly of hemicelluloses to discover their full application potential. Click on the title for more information.
Carbohydrate-attached fullerene derivative for selective localization in ordered carbohydrate-block-poly(3-hexylthiophene) nanodomains
Towards photovoltaic devices made from highly nano-organised carbohydrate block copolymers. Click on the title for more information.
Non‐Carbohydrate Glycomimetics as Inhibitors of Calcium(II)‐binding Lectins
Search for new inhibitors of bacterial infection is a priority for fighting antibiotics resistance, and this is the topic of a french-german ANR-DFG project. We screened for libraries of non-carbohydrate ligands for binding to Pseudomonas aeruginosa calcium-dependent lectins, and identified catechol derivatives as interesting lead. The first co‐crystal structure of a non‐carbohydrate inhibitor in complex with a bacterial lectin clearly demonstrates the catechol mimicking the binding of natural glycosides with LecA. Interstingly, catechol derivatives also bind to human C-type lectins, opening a wide range of applications. Click on the title for more information.
Happy New Year!
Both CNRS and Cermav wish you a happy New Year and all the best for 2021. Click on the title to watch the video.
Season’s Greeting
Cermav wishes you a happy holidays!
GAG-DB, the New Interface of the Three-Dimensional Landscape of Glycosaminoglycans
Glycosaminoglycans (GAGs) are complex linear polysaccharides. GAG-DB is a curated database that classifies the three-dimensional features of the six mammalian GAGs (chondroitin sulfate, dermatan sulfate, heparin, heparan sulfate, hyaluronan, and keratan sulfate) and their oligosaccharides complexed with proteins. GAG-DB provides detailed information on GAGs, their bound protein ligands, and features their interactions using several open access applications. Binding covers interactions between monosaccharides and protein monosaccharide units and the evaluation of quaternary structure. Click on the title for more information.
