Modification of linear ({beta}1->3)-linked gluco-oligosaccharides with a novel recombinant {beta}-glucosyltransferase (trans-{beta}-glucosidase) enzyme from Bradyrhizobium diazoefficiens
Recently, we have shown that glycoside hydrolases enzymes of family GH17 from proteobacteria (genera Pseudomonas, Azotobacter) catalyze elongation transfer reactions with laminari-oligosaccharides generating (β1->3) linkages preferably and to a lesser extent (β1->6) or (β1->4) linkages. In the present study, the cloning and characterization of the gene encoding the structurally very similar GH17 domain of the NdvB enzyme from Bradyrhizobium diazoefficiens, designated Glt20, as well as its catalytic properties are described. The Glt20 enzyme was strikingly different from the previously investigated b...
Source: Glycobiology - November 21, 2016 Category: Biology Authors: Dobruchowska, J. M., Jonsson, J. O., Fridjonsson, O. H., Aevarsson, A., Kristjansson, J. K., Altenbuchner, J., Watzlawick, H., Gerwig, G. J., Dijkhuizen, L., Kamerling, J. P., Hreggvidsson, G. O. Tags: Analytical Glycobiology Source Type: research
Improved workflow for the efficient preparation of ready to use CMP-activated sialic acids
Natural and synthetically modified cytidine monophosphate activated sialic acids (CMP-Sias) are essential research assets in the field of glycobiology: among other applications, they can be used to probe glycans, detect sialylation defects at the cell surface or carry out detailed studies of sialyltransferase activities. However, these chemical tools are notoriously unstable because of hydrolytic decomposition, and are very time-consuming and costly to obtain. They are nigh impossible to store with satisfactory purity, and their preparation requires multiple laborious purification steps that usually lead to heavy product l...
Source: Glycobiology - November 21, 2016 Category: Biology Authors: Gilormini, P.-A., Lion, C., Noel, M., Krzewinski-Recchi, M.-A., Harduin-Lepers, A., Guerardel, Y., Biot, C. Tags: Chemical Biology Source Type: research
Natural anti-carbohydrate antibodies contributing to evolutionary survival of primates in viral epidemics?
Humans produce multiple natural antibodies against carbohydrate antigens on gastrointestinal bacteria. Two such antibodies appeared in primates in recent geological times. Anti-Gal, abundant in humans, apes and Old-World monkeys, appeared 20–30 million years ago (mya) following inactivation of the α1,3GT gene (GGTA1). This gene encodes in other mammals the enzyme α1,3galactosyltransferase (α1,3GT) that synthesizes α-gal epitopes (Galα1-3Galβ1-4GlcNAc-R) which bind anti-Gal. Anti-Neu5Gc, found only in humans, appeared in hominins <6 mya, following elimination of N-glycolylneuramin...
Source: Glycobiology - November 21, 2016 Category: Biology Authors: Galili, U. Tags: Review Source Type: research
A chicken vaccine to protect humans from diarrheal disease
(Source: Glycobiology)
Source: Glycobiology - November 21, 2016 Category: Biology Authors: Avci, F. Y. Tags: Letter to the Glyco-Forum Source Type: research
Emil Fischer Carbohydrate Award 2017
(Source: Glycobiology)
Source: Glycobiology - November 21, 2016 Category: Biology Authors: The European Carbohydrate Organization is delighted to announce that the Emil Fischer Award for 2017 has been awarded to Prof. Carlo Unverzagt Tags: Glyco-Forum Section Source Type: research
Meeting and Course Announcements
(Source: Glycobiology)
Source: Glycobiology - November 21, 2016 Category: Biology Tags: Glyco-Forum Section Source Type: research
Subscription Page
(Source: Glycobiology)
Source: Glycobiology - November 21, 2016 Category: Biology Tags: Cover/Standing Material Source Type: research
Editorial Board
(Source: Glycobiology)
Source: Glycobiology - November 21, 2016 Category: Biology Tags: Cover/Standing Material Source Type: research
Contents Page
(Source: Glycobiology)
Source: Glycobiology - November 21, 2016 Category: Biology Tags: Cover/Standing Material Source Type: research
Differentiation-related glycan epitopes identify discrete domains of the muscle glycocalyx
The neuromuscular junction (NMJ) is enriched with glycoproteins modified with N-acetylgalactosamine (GalNAc) residues, and four nominally GalNAc-specific plant lectins have historically been used to identify the NMJ and the utrophin–glycoprotein complex. However, little is known about the specific glycan epitopes on skeletal muscle that are bound by these lectins, the glycoproteins that bear these epitopes or how creation of these glycan epitopes is regulated. Here, we profile changes in cell surface glycosylation during muscle cell differentiation and identify distinct differences in the binding preferences of GalNA...
Source: Glycobiology - October 18, 2016 Category: Biology Authors: McMorran, B. J., McCarthy, F. E., Gibbs, E. M., Pang, M., Marshall, J. L., Nairn, A. V., Moremen, K. W., Crosbie-Watson, R. H., Baum, L. G. Tags: Translational Glycobiology Source Type: research
Discovery and characterization of de novo sialic acid biosynthesis in the phylum Fusobacterium
Sialic acids are nine-carbon backbone carbohydrates found in prominent outermost positions of glycosylated molecules in mammals. Mimicry of sialic acid (N-acetylneuraminic acid, Neu5Ac) enables some pathogenic bacteria to evade host defenses. Fusobacterium nucleatum is a ubiquitous oral bacterium also linked with invasive infections throughout the body. We employed multidisciplinary approaches to test predictions that F. nucleatum engages in de novo synthesis of sialic acids. Here we show that F. nucleatum sbsp. polymorphum ATCC10953 NeuB (putative Neu5Ac synthase) restores Neu5Ac synthesis to an Escherichia coli neuB muta...
Source: Glycobiology - October 18, 2016 Category: Biology Authors: Lewis, A. L., Robinson, L. S., Agarwal, K., Lewis, W. G. Tags: Microbial Biology Source Type: research
Two N-terminally truncated variants of human {beta}-galactoside {alpha}2,6 sialyltransferase I with distinct properties for in vitro protein glycosylation
We report on the distinct properties of two N-terminally truncated versions of ST6Gal-I, namely 89ST6Gal-I and 108ST6Gal-I, which were successfully expressed in human embryonic kidney cells. The different properties of these enzymes result most probably from the loss of interactions from helix α1 in the 108ST6Gal-I variant, which plays a role in acceptor substrate binding. The Km for N-acetyl-d-lactosamine was 10-fold increased for 108ST6Gal-I (84 mM) as compared to 89ST6Gal-I (8.3 mM). The two enzyme variants constitute a suitable tool box for the terminal modification of N-glycans. While the enzyme 89ST6Gal-I exhib...
Source: Glycobiology - October 18, 2016 Category: Biology Authors: Luley-Goedl, C., Schmoelzer, K., Thomann, M., Malik, S., Greif, M., Ribitsch, D., Jung, C., Sobek, H., Engel, A., Mueller, R., Schwab, H., Nidetzky, B. Tags: Glycan Synthesis Source Type: research
Generation and characterization of {beta}1,2-gluco-oligosaccharide probes from Brucella abortus cyclic {beta}-glucan and their recognition by C-type lectins of the immune system
We describe optimized conditions for partial depolymerization of the cyclic glucan by acid hydrolysis and conversion of the β1,2-gluco-oligosaccharides, with degrees of polymerization 2–13, to neoglycolipids for the purpose of generating microarrays. By microarray analyses, we show that the C-type lectin receptor DC-SIGNR, like the closely related DC-SIGN we investigated earlier, binds to the β1,2-gluco-oligosaccharides, as does the soluble immune effector serum mannose-binding protein. Exploratory studies with DC-SIGN are suggestive of the recognition also of the intact CβG by this receptor. These fin...
Source: Glycobiology - October 18, 2016 Category: Biology Authors: Zhang, H., Palma, A. S., Zhang, Y., Childs, R. A., Liu, Y., Mitchell, D. A., Guidolin, L. S., Weigel, W., Mulloy, B., Ciocchini, A. E., Feizi, T., Chai, W. Tags: Original articles Source Type: research
Occurrence of free sialyl oligosaccharides related to N-glycans (sialyl free N-glycans) in animal sera
In this study we demonstrate the wide occurrence of sialylated FNGs in sera of various animals. The features of these extracellular FNGs are quite distinct from the cytosolic FNGs, as they are Gn2-type glycans, bearing an N,N'-diacetylchitobiose unit at their reducing termini, while the cytosolic FNGs are predominantly Gn1-type, with a single GlcNAc at their reducing termini. The major structures observed varied from species to species, and the structures of the FNGs appear to be correlated with the major sialyl N-glycans on serum glycoproteins, suggesting that the serum FNGs are produced by hepatocytes. Interestingly, gly...
Source: Glycobiology - October 18, 2016 Category: Biology Authors: Seino, J., Fujihira, H., Nakakita, S.-i., Masahara-Negishi, Y., Miyoshi, E., Hirabayashi, J., Suzuki, T. Tags: Glycan Metabolism Source Type: research
Base-modified UDP-sugars reduce cell surface levels of P-selectin glycoprotein 1 (PSGL-1) on IL-1{beta}-stimulated human monocytes
P-selectin glycoprotein ligand-1 (PSGL-1, CD162) is a cell-surface glycoprotein that is expressed, either constitutively or inducibly, on all myeloid and lymphoid cell lineages. PSGL-1 is implicated in cell–cell interactions between platelets, leukocytes and endothelial cells, and a key mediator of inflammatory cell recruitment and transmigration into tissues. Here, we have investigated the effects of the β-1,4-galactosyltransferase inhibitor 5-(5-formylthien-2-yl) UDP-Gal (5-FT UDP-Gal, compound 1) and two close derivatives on the cell surface levels of PSGL-1 on human peripheral blood mononuclear cells (hPBMCs...
Source: Glycobiology - October 18, 2016 Category: Biology Authors: Kanabar, V., Tedaldi, L., Jiang, J., Nie, X., Panina, I., Descroix, K., Man, F., Pitchford, S. C., Page, C. P., Wagner, G. K. Tags: Chemical Biology Source Type: research
