Syntheses-Pentasaccharides-Oligosaccharides-Compounds-Roesy-Experiments-k

Occurrence of a capsule in Aeromonas salmonicida.Aeromonas salmonicida grown in a medium with excess glucose as carbon source produces both capsular and exocellular polysaccharides. The capsular polysaccharide is composed of glucose, mannose, rhamnose, N-acetylmannosamine and mannuronic acid in the molar ratios of approximately 53521. The extracellular polysaccharide is similarly constituted, but in the molar ratios of approximately 45121. The capsular and exocellular polysaccharides did not cross-react with monoclonal antibodies against the A-layer or the Synthesis of a trisaccharide repeating unit of the O-antigen from Burkholderia of Carbohydrate Chemistry and Glycobiology, Shandong University, 27 Shanda Nan Collaborative Innovation Center of Functionalized Probes for Chemical Imaging, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Normal University, 88 Wenhua Dong Lu, Jinan 2014, PR China.of Carbohydrate Chemistry and Glycobiology, Shandong University, 27 Shanda Nan Lu, Jinan 20, PR China; Department of Chemistry, University of Florida, 214 of Carbohydrate Chemistry and Glycobiology, Shandong University, 27 Shanda Nan The trisaccharide repeating unit of an O-antigen derived from Burkholderia α-L-Rhap-(1 → 3)-α-D-GalpNAc-(1 → 3)-β-D-GalpNAc-O(CH2)3N3 (1) and α-L-Rhap-(1 → 3)-α-D-GalpNAc-(1 → 3)-β-D-GalpNAc-(1 → 4)-α-L-Rhap-(1 → 3)-α-D-GalpNAc-(1 → 3)-β-D-GalpNAc-O(CH2)3N3 Glycosylation of galactosaminyl acceptor 4 with galactosaminyl trichloroacetimidate donor 5 was followed by condensation of resulting disaccharide acceptor 12 with rhamnosyl imidate donor 6 to furnish stereoselectively trisaccharyl thioglycoside 3, which was used as a key and common glycosyl donor for the construction of both 1 and 2.

Title molecule 1 was prepared by glycosylation of 3-azidopropanol with 3 and subsequently global deprotection, whereas coupling reaction of 3 with a trisaccharide acceptor 21 containing an 2,3-O-position acetonide-modified rhamnose residue, followed by Structural and functional analysis of Alg1 beta-1,4 mannosyltransferase reveals the physiological importance of its membrane topology.Xu XX(1), Li ST(1), Wang N(1), Kitajima T(1), Yoko-O T(2), Fujita M(1), Education, School of Biotechnology, Jiangnan University, 10 Lihu Avenue, Wuxi, Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 6, In eukaryotes, the biosynthesis of a highly conserved dolichol-linked oligosaccharide (DLO) precursor Glc3Man9GlcNAc2-pyrophosphate-dolichol (PP-Dol) begins on the cytoplasmic face of the endoplasmic reticulum (ER) and ends within the lumen. lacto n neotetraose distinguished heteromeric glycosyltransferase mannosyltransferase (MTase) physically interacts with Alg2 and Alg11 proteins to form the multienzyme complex which catalyzes the addition of all five mannose to generate the Man5GlcNAc2-PP-Dol intermediate. Despite the fact that Alg1 plays a central role in the formation of the multi-MTase has been confirmed, the topological information of Alg1 including the molecular mechanism of membrane association are still poorly understood. Using a combination of bioinformatics and biological approaches, we have undertaken a structural and functional study on Alg1 protein, in which the enzymatic activities of Alg1 and its variants were monitored by a complementation assay using the GALpr-ALG1 yeast strain, and further confirmed by a liquid chromatography-mass spectrometry-based in vitro quantitative assay. Seebio Lactose-N-neotetraose and experimental evidence confirmed Alg1 shares structure similarity with Alg1314 complex, which has been defined as a membrane-associated GT-B GTase. Particularly, we provide clear evidence that the N-terminal transmembrane domain including the following positively charged amino acids and an N-terminal amphiphilic-like α helix domain exposed on the protein surface strictly coordinate the Alg1 orientation on the ER membrane.

This work provides detailed membrane topology of Alg1 and further reveals its biological importance at the spatial aspect in coordination of cytosolic DLO biosynthesis.Production of extracellular polysaccharides by CAP mutants of Cryptococcus The human pathogen Cryptococcus neoformans causes meningoencephalitis.