Author
Anne Imberty
Other affiliations: Bar-Ilan University, Joseph Fourier University, Institut national de la recherche agronomique ...read more
Bio: Anne Imberty is an academic researcher from University of Grenoble. The author has contributed to research in topics: Lectin & Binding site. The author has an hindex of 74, co-authored 381 publications receiving 18759 citations. Previous affiliations of Anne Imberty include Bar-Ilan University & Joseph Fourier University.
Topics: Lectin, Binding site, Glycan, Fucose, C-type lectin
Papers published on a yearly basis
Papers
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TL;DR: The 3D-Glycosyltransferase database is created to gather structural information concerning this class of enzymes and to accommodate the growing number of crystal structures.
Abstract: Glycosyltransferases (GTs) catalyze the transfer of a sugar moiety from an activated donor sugar onto saccharide and nonsaccharide acceptors A sequence-based classification spreads GTs in many families thus reflecting the variety of molecules that can be used as acceptors In contrast, this enzyme family is characterized by a more conserved three-dimensional architecture Until recently, only two different folds (GT-A and GT-B) have been identified for solved crystal structures The recent report of a structure for a bacterial sialyltransferase allows the definition of a new fold family Progress in the elucidation of the structures and mechanisms of GTs are discussed in this review To accommodate the growing number of crystal structures, we created the 3D-Glycosyltransferase database to gather structural information concerning this class of enzymes
602 citations
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TL;DR: A new three-dimensional structure of the crystalline part of A-starch is described in which the unit cell contains 12 glucose residues located in two left-handed, parallel-stranded double helices packed in a parallel fashion; four water molecules are located between these helices.
561 citations
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TL;DR: In this paper, three dimensional models of crystalline zones and amorphous branching zones of starch granules are reviewed, where double helices are found in pairs, and all chains are packed in parallel arrays.
Abstract: Three dimensional models of crystalline zones and amorphous branching zones of starch granules are reviewed. In crystallites of both A and B starch, double helices are found in pairs, and all chains are packed in parallel arrays. The pairing of double helices is identical in both polymorphs and corresponds to the interaction between double helices that has the lowest energy. The differences between A and B starch arise from water content and the manner in which these pairs are packed in the respective crystals. A transition from B starch to the A form can be accomplished by rearrangement of the pairs of double helices. The 1–6 linked amylopectin branch points occur in amorphous regions, but actually promote the formation of ordered double helices.
509 citations
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TL;DR: Wu et al. as mentioned in this paper proposed a new three-dimensional structure of B-starch in which the unit cell contains 12 glucose residues located in two left-handed, parallel-stranded double helices packed in a parallel register; 36 water molecules are located between these helices.
Abstract: A new three-dimensional structure of B-starch is proposed in which the unit cell contains 12 glucose residues located in two left-handed, parallel-stranded double helices packed in a parallel register; 36 water molecules are located between these helices. Chains are crystallized in the hexagonal space group P61, with lattice parameters a = b = 1.85 nm, c = 1.04 nm. The space group symmetry was derived from an exhaustive analysis of the large body of structural studies published so far. Diffraction data used in this work were taken from the previously reported x-ray fiber diffractogram [H.C. Wu and A. Sarko (1978), Carbohydrate Research, 61, 7–25] after adequate reindexing. The final R factor is 0.145 for the three-dimensional data. The repeating unit consists of a maltose molecule where the glucose residues have the 4C1 pyranose conformation and are α(1 → 4) linked. The conformation of the glycosidic linkage is characterized by torsion angles (Φ, Ψ) that take the values (83.8°, −144.6°) and (84.3°, −144.1°), whereas the valence angles at the glycosidic bridge have a magnitude of 115.8° and 116.5°, respectively. The primary hydroxyl groups exist in a gauche–gauche conformation. There is no intramolecular hydrogen bond. Within the double helix, interstrand stabilization is achieved without any steric conflict and through the occurrence of O(2)…O(6) type of hydrogen bonds. The model presented here, with an hydration around 27% w/w, corresponds to a well-ordered crystalline sample, since all the water molecules could be located with no apparent sign of a disorder. Half of the water molecules are tightly bound to the double helices; the remainder forms a complex network centered around the sixfold screw axis of the unit cell. The consistency of the present structural model, with both physicochemical and biochemical aspects of the crystalline component of tuber starch granules, is analyzed.
493 citations
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University of Milan1, Spanish National Research Council2, University of Parma3, University of Bern4, University of Helsinki5, University of Düsseldorf6, Bangor University7, University of Kiel8, University of Natural Resources and Life Sciences, Vienna9, National University of Ireland, Galway10, University of Florence11, University College Dublin12, University of Milano-Bicocca13, Utrecht University14, Joseph Fourier University15, University of Seville16, University of Leeds17, Maynooth University18, Claude Bernard University Lyon 119, Université de Namur20, Wageningen University and Research Centre21, King Abdulaziz University22, University of Grenoble23
TL;DR: By interfering with pathogen adhesion, such glycocompounds including glycopolymers, glycoclusters, glycodendrimers and glyconanoparticles have the potential to improve or replace antibiotic treatments that are now subverted by resistance.
Abstract: Multivalency plays a major role in biological processes and particularly in the relationship between pathogenic microorganisms and their host that involves protein-glycan recognition. These interactions occur during the first steps of infection, for specific recognition between host and bacteria, but also at different stages of the immune response. The search for high-affinity ligands for studying such interactions involves the combination of carbohydrate head groups with different scaffolds and linkers generating multivalent glycocompounds with controlled spatial and topology parameters. By interfering with pathogen adhesion, such glycocompounds including glycopolymers, glycoclusters, glycodendrimers and glyconanoparticles have the potential to improve or replace antibiotic treatments that are now subverted by resistance. Multivalent glycoconjugates have also been used for stimulating the innate and adaptive immune systems, for example with carbohydrate-based vaccines. Bacteria present on their surfaces natural multivalent glycoconjugates such as lipopolysaccharides and S-layers that can also be exploited or targeted in anti-infectious strategies.
449 citations
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TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.
Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …
33,785 citations
28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。
18,940 citations
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TL;DR: A new method, based on chemical thermodynamics, is developed for automatic detection of macromolecular assemblies in the Protein Data Bank (PDB) entries that are the results of X-ray diffraction experiments, as found, biological units may be recovered at 80-90% success rate, which makesX-ray crystallography an important source of experimental data on macromolescular complexes and protein-protein interactions.
8,377 citations
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TL;DR: Chitin is the second most important natural polymer in the world as mentioned in this paper, and the main sources of chitin are two marine crustaceans, shrimp and crabs, which are used for food, cosmetics, biomedical and pharmaceutical applications.
6,365 citations
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TL;DR: The structural requirements of peptides for antiviral and antibacterial activities are evaluated in light of the diverse set of primary and secondary structures described for host defense peptides.
Abstract: Antimicrobial host defense peptides are produced by all complex organisms as well as some microbes and have diverse and complex antimicrobial activities. Collectively these peptides demonstrate a broad range of antiviral and antibacterial activities and modes of action, and it is important to distinguish between direct microbicidal and indirect activities against such pathogens. The structural requirements of peptides for antiviral and antibacterial activities are evaluated in light of the diverse set of primary and secondary structures described for host defense peptides. Peptides with antifungal and antiparasitic activities are discussed in less detail, although the broad-spectrum activities of such peptides indicate that they are important host defense molecules. Knowledge regarding the relationship between peptide structure and function as well as their mechanism of action is being applied in the design of antimicrobial peptide variants as potential novel therapeutic agents.
2,231 citations