ArnT proteins that catalyze the glycosylation of lipopolysaccharide share common features with bacterial N-oligosaccharyltransferases
We report here the identification of a functional motif with a canonical consensus sequence DEXRYAX(5)MX(3)GXWX(9)YFEKPX(4)W spanning the first periplasmic loop, which is highly conserved in all ArnT proteins examined. Site-directed mutagenesis demonstrated the contribution of this motif in ArnT function, suggesting that these proteins have a common mechanism. We also demonstrate that the Burkholderia cenocepacia and Salmonella enterica serovar Typhimurium ArnT C-terminal domain is required for polymyxin B resistance in vivo. Deletion of the C-terminal domain in B. cenocepacia ArnT resulted in a protein with significantly ...
Source: Glycobiology - February 2, 2016 Category: Biology Authors: Tavares-Carreon, F., Fathy Mohamed, Y., Andrade, A., Valvano, M. A. Tags: Microbial Biology Source Type: research
Schistosoma mansoni {alpha}1,3-fucosyltransferase-F generates the Lewis X antigen
Genetic evidence suggests that the Schistosoma mansoni genome contains six genes that encode α1,3-fucosyltransferases (smFuTs). To date, the activities and specificities of these putative fucosyltransferases are unknown. As Schistosoma express a variety of fucosylated glycans, including the Lewis X antigen Galβ1–4(Fucα1–3)GlcNAcβ-R, it is likely that this family of genes encode enzymes that are partly responsible for the generation of those structures. Here, we report the molecular cloning of fucosyltransferase-F (smFuT-F) from S. mansoni, as a soluble, green fluorescent protein fusion pro...
Source: Glycobiology - February 2, 2016 Category: Biology Authors: Mickum, M. L., Rojsajjakul, T., Yu, Y., Cummings, R. D. Tags: Glycan Synthesis Source Type: research
Design of an {alpha}-L-transfucosidase for the synthesis of fucosylated HMOs
Human milk oligosaccharides (HMOs) are recognized as benefiting breast-fed infants in multiple ways. As a result, there is growing interest in the synthesis of HMOs mimicking their natural diversity. Most HMOs are fucosylated oligosaccharides. α-l-Fucosidases catalyze the hydrolysis of α-l-fucose from the non-reducing end of a glucan. They fall into the glycoside hydrolase GH29 and GH95 families. The GH29 family fucosidases display a classic retaining mechanism and are good candidates for transfucosidase activity. We recently demonstrated that the α-l-fucosidase from Thermotoga maritima (TmαFuc) fro...
Source: Glycobiology - February 2, 2016 Category: Biology Authors: Saumonneau, A., Champion, E., Peltier-Pain, P., Molnar-Gabor, D., Hendrickx, J., Tran, V., Hederos, M., Dekany, G., Tellier, C. Tags: Glycan Synthesis Source Type: research
Roles of glycans in interactions between gp120 and HIV broadly neutralizing antibodies
In this study, we have investigated the critical roles of glycans in interactions between HIV-1 gp120 and two broadly neutralizing antibodies PG9 (targeting V1/V2) and PGT128 (targeting V3) that are able to neutralize more than 70% of HIV-1 isolates. We have performed molecular dynamics simulations of a number of systems including antibody–gp120 complex with and without glycans, antibody, gp120 with and without glycans, and glycan-only systems. The simulation results show that the complex structures are stabilized by the glycans, and the multivalent interactions between the antibody and gp120 promote cooperativities ...
Source: Glycobiology - February 2, 2016 Category: Biology Authors: Qi, Y., Jo, S., Im, W. Tags: Computational Biology Source Type: research
Structural characterization and biological implications of sulfated N-glycans in a serine protease from the neotropical moth Hylesia metabus (Cramer [1775]) (Lepidoptera: Saturniidae)
Contact with the urticating setae from the abdomen of adult females of the neo-tropical moth Hylesia metabus gives rise to an urticating dermatitis, characterized by intense pruritus, generalized malaise and occasionally ocular lesions (lepidopterism). The setae contain a pro-inflammatory glycosylated protease homologous to other S1A serine proteases of insects. Deglycosylation with PNGase F in the presence of a buffer prepared with 40% H218O allowed the assignment of an N-glycosylation site. Five main paucimannosidic N-glycans were identified, three of which were exclusively α(1–6)-fucosylated at the proximal ...
Source: Glycobiology - February 2, 2016 Category: Biology Authors: Cabrera, G., Salazar, V., Montesino, R., Tambara, Y., Struwe, W. B., Leon, E., Harvey, D. J., Lesur, A., Rincon, M., Domon, B., Mendez, M., Portela, M., Gonzalez-Hernandez, A., Triguero, A., Duran, R., Lundberg, U., Vonasek, E., Gonzalez, L. J. Tags: Analytical Glycobiology Source Type: research
Sweating the small stuff: Glycoproteins in human sweat and their unexplored potential for microbial adhesion
There is increasing evidence that secretory fluids such as tears, saliva and milk play an important role in protecting the human body from infection via a washing mechanism involving glycan-mediated adhesion of potential pathogens to secretory glycoproteins. Interaction of sweat with bacteria is well established as the cause of sweat-associated malodor. However, the role of sweat glycoproteins in microbial attachment has received little, if any, research interest in the past. In this review, we demonstrate how recent published studies involving high-throughput proteomic analysis have inadvertently, and fortuitously, expose...
Source: Glycobiology - February 2, 2016 Category: Biology Authors: Peterson, R. A., Gueniche, A., Adam de Beaumais, S., Breton, L., Dalko-Csiba, M., Packer, N. H. Tags: REVIEW Source Type: research
Symbol Nomenclature for Glycans (SNFG)
(Source: Glycobiology)
Source: Glycobiology - February 2, 2016 Category: Biology Authors: Haltiwanger, R. S. Tags: GLYCO-FORUM Source Type: research
Meeting and Course Announcements
(Source: Glycobiology)
Source: Glycobiology - February 2, 2016 Category: Biology Tags: GLYCO-FORUM Source Type: research
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(Source: Glycobiology)
Source: Glycobiology - February 2, 2016 Category: Biology Tags: Cover/Standing Material Source Type: research
Editorial Board
(Source: Glycobiology)
Source: Glycobiology - February 2, 2016 Category: Biology Tags: Cover/Standing Material Source Type: research
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(Source: Glycobiology)
Source: Glycobiology - February 2, 2016 Category: Biology Tags: Cover/Standing Material Source Type: research
Candida albicans {beta}-1,2-mannosyltransferase Bmt3 prompts the elongation of the cell-wall phosphopeptidomannan
β-1,2-Linked mannosides are expressed on numerous cell-wall glycoconjugates of the opportunistic pathogen yeast Candida albicans. Several studies evidenced their implication in the host–pathogen interaction and virulence mechanisms. In the present study, we characterized the in vitro activity of CaBmt3, a β-1,2-mannosyltransferase involved in the elongation of β-1,2-oligomannosides oligomers onto the cell-wall polymannosylated N-glycans. A recombinant soluble enzyme Bmt3p was produced in Pichia pastoris and its enzyme activity was investigated using natural and synthetic oligomannosides as potential ac...
Source: Glycobiology - December 26, 2015 Category: Biology Authors: Sfihi-Loualia, G., Hurtaux, T., Fabre, E., Fradin, C., Mee, A., Pourcelot, M., Maes, E., Bouckaert, J., Mallet, J.-M., Poulain, D., Delplace, F., Guerardel, Y. Tags: Microbial Biology Source Type: research
Characterization of a family 43 {beta}-xylosidase from the xylooligosaccharide utilizing putative probiotic Weissella sp. strain 92
In this work, we present the first XOS degrading glycoside hydrolase from Weissella, WXyn43, a two-domain enzyme from GH43. The gene was amplified from genomic DNA of the XOS utilizing Weissella strain 92, classified under the species-pair Weissella cibaria/W.confusa, and expressed in Escherichia coli. The enzyme is lacking a putative signal peptide and is, from a homology model, shown to be composed of an N-terminal 5-fold β-propeller catalytic domain and a C-terminal β-sandwich domain of unknown function. WXyn43 hydrolyzed short (1–4)-β-d-xylooligosaccharides, with similar kcat/KM for xylobiose (X2) ...
Source: Glycobiology - December 26, 2015 Category: Biology Authors: Falck, P., Linares-Pasten, J. A., Adlercreutz, P., Karlsson, E. N. Tags: Microbial Biology Source Type: research
Single-chain antibody-fragment M6P-1 possesses a mannose 6-phosphate monosaccharide-specific binding pocket that distinguishes N-glycan phosphorylation in a branch-specific manner
The acquisition of mannose 6-phosphate (Man6P) on N-linked glycans of lysosomal enzymes is a structural requirement for their transport from the Golgi apparatus to lysosomes mediated by the mannose 6-phosphate receptors, 300 kDa cation-independent mannose 6-phosphate receptor (MPR300) and 46 kDa cation-dependent mannose 6-phosphate receptor (MPR46). Here we report that the single-chain variable domain (scFv) M6P-1 is a unique antibody fragment with specificity for Man6P monosaccharide that, through an array-screening approach against a number of phosphorylated N-glycans, is shown to bind mono- and diphosphorylated Man6 and...
Source: Glycobiology - December 26, 2015 Category: Biology Authors: Blackler, R. J., Evans, D. W., Smith, D. F., Cummings, R. D., Brooks, C. L., Braulke, T., Liu, X., Evans, S. V., Müller-Loennies, S. Tags: Glycan Recognition Source Type: research
Inhibition of Rab prenylation by statins induces cellular glycosphingolipid remodeling
Statins, which specifically inhibit HMG Co-A reductase, the rate-limiting step of cholesterol biosynthesis, are widely prescribed to reduce serum cholesterol and cardiac risk, but many other effects are seen. We now show an effect of these drugs to induce profound changes in the step-wise synthesis of glycosphingolipids (GSLs) in the Golgi. Glucosylceramide (GlcCer) was increased several-fold in all cell lines tested, demonstrating a widespread effect. Additionally, de novo or elevated lactotriaosylceramide (Lc3Cer; GlcNAcβ1-3Galβ1-4GlcCer) synthesis was observed in 70%. Western blot showed that GlcCer synthase (...
Source: Glycobiology - December 26, 2015 Category: Biology Authors: Binnington, B., Nguyen, L., Kamani, M., Hossain, D., Marks, D. L., Budani, M., Lingwood, C. A. Tags: Glycan Metabolism Source Type: research
