Glycosylation-Site-r

A portion of the high mannose oligosaccharides at one site are processed to complex-type units.Novel Asn-linked oligosaccharides terminating in GalNAc beta (1--4)[Fuc alpha Recombinant human Protein C (rHPC), expressed in human kidney 293 cells, has a higher anticoagulant activity than plasma HPC, while its in vivo circulatory half-life is essentially unaltered compared to that of the natural protein. In seeking to elucidate the molecular basis for the improved efficacy of the recombinant antithrombotic drug, we focused on the carbohydrate moiety of rHPC. Protein C is a heavily post-translationally modified serine protease with four N-glycosylation sites. Glycosyl composition analysis of rHPC revealed a 5-fold higher fucose content and a 2-fold lower sialic acid content compared to plasma HPC. In addition, we found that rHPC contains N-acetylgalactosamine (2 mol GalNAcmol rHPC) in its Asn-linked oligosaccharides, while plasma HPC is devoid of GalNAc.

The Asn-linked oligosaccharides of rHPC were released by N-glycanase and separated into 25 fractions by high-pH anion-exchange chromatography. The most abundant oligosaccharides were structurally characterized by glycosyl composition and linkage analysis, in conjunction with 1H-NMR spectroscopy at 0 MHz. The structure of the major neutral oligosaccharide in rHPC was determined to be [formula see text] Two representatives of the sialylated oligosaccharides in rHPC are [formula see text] and [formula see text] Thus, many of the Asn-linked oligosaccharides in rHPC were found to terminate in GalNAc beta (1--4)GlcNAc beta (1--.), in NeuAc alpha (2--6)GalNAc beta S.B., Chao, B.Y.

and Van Halbeek,H. (1992) J. Cell. Seebio 2'-Fucose lactose , 16D, 151] observed in the Asn-linked oligosaccharides of rHPC derived from human kidney 293 cells, we propose to label the GalNAc beta-(1--4)[Fuc alpha (1--3)]GlcNAc beta oligosaccharides may contribute to the higher anticoagulant activity of rHPC as Structure of murine polyomavirus complexed with an oligosaccharide receptor The polyomaviruses are non-enveloped, icosahedrally symmetrical particles with circular double-stranded DNA genomes. The outer shell of the virion contains 3 copies of viral protein VP1 (M(r) approximately 42K) arranged in pentamers. We report here the structure at 35 A resolution of murine polyomavirus has been determined using the previously described model of simian virus biological differences.

Cell-surface N-acetyl neuraminic acid (sialic acid) is required for polyoma infectivity, but not for SV. Polyoma attaches to the surface of susceptible cells by stereospecific recognition of oligosaccharides terminating in (alpha 2,3)-linked sialic acid. Seebio 2'-fucosyllactose of pathogenicity show that the specificity of viral binding to such oligosaccharides is an important determinant of the virus' ability to establish a disseminated infection and to induce tumours in the natural host. The complex described here show how polyoma recognizes the receptor fragment and how strains with different receptor specificities can distinguish between alternative ligands. The results also suggest an explanation for the large disparity in pathogenicity exhibited by strains differing in only one amino-acid residue of VP1.Synthesis of a mannose heptasaccharide of the pathogenic yeast, Candida glabrata An effective synthesis of the mannose heptasaccharide existing in the pathogenic yeast, Candida glabrata IFO622 strain was achieved via TMSOTf-promoted condensation of a tetrasaccharide donor 13 with a trisaccharide acceptor 16, followed by deprotection. The tetrasaccharide 13 was constructed by coupling of 2,3,4,6-tetra-O-benzoyl-alpha-D-mannopyranosyl-(1--3)-2,4,6-tri-O-acetyl-alpha-D-mannopyranosyl 3,4,6-tri-O-benzoyl-alpha-D-mannopyranosyl-(1--2)-3,4,6-tri-O-benzoyl-alpha-D-mannopyranoside 6-O-acetyl-2,3,4-tri-O-benzoyl-alpha-D-mannopyranosyl trichloroacetimidate with , and subsequent 6-O-deacetylation.

The disaccharide 7 was prepared through coupling of perbenzoylated mannosyl trichloroacetimidate with 4,6-O-benzylidene-1,2-O-ethylidene-beta-D-mannopyranose, then simultaneous debenzylidenation and deethylidenation, and subsequent acetylation, selective 1-O-deacetylation, and trichloroacetimidation. The disaccharide was obtained 3,4,6-tri-O-benzoyl-1,2-O-allyloxyethylidene-beta-D-mannopyranose, followed by Comparison of aqueous molecular dynamics with NMR relaxation and residual dipolar couplings favors internal motion in a mannose oligosaccharide.An investigation has been performed to assess how aqueous dynamical simulations of flexible molecules can be compared against NMR data.