Assignment of intrachain disulfide bonds and characterization of potential glycosylation sites of the type 1 recombinant human immunodeficiency virus envelope glycoprotein (gp120) expressed in Chinese hamster ovary cells.

Publisher Summary This chapter provides an overview of the primary structure of glycoprotein glycans. There exists a certain unity of structure among glycans. All are derived by the substitution of common, core oligosaccharides ( inv fractions) by variable oligosaccharide structures ( var fractions), which are the basis of their specificity. The var fractions present a limited number of the types of structure. In the case of N -glycosylproteins, in which the glycan-protein bond is asparaginyl-2-acetamido-2-deoxyglucose, the glycans are of three fundamental types: the oligomannosidic, the N -acetyllactosaminic, and the mixed, oligomannosidic- N -acetyl-lactosaminic. The determination of the structures of oligosaccharides from the urines of glycoproteinoses, diseases characterized by a deficit in lysosomal enzymes catabolizing the glycans of glycoprotein, allows reconstruction of the different stages of glycoprotein catabolism, and presentation of the hypothesis that the catabolism of N -acetyl-lactosainine glycans starts by the action of endo-2-acetamido-2-deoxy-β- D -glucosidases in liberating oligosaccharides that are then degraded by exoglycosidases. This chapter elaborates the primary structure and metabolism of the N -linked glycans. Development and improvement of procedures for the study of the primary structure of glycans is also discussed.

Primary structure of glycoprotein glycans: basis for the molecular biology of glycoproteins.

Structural determinants of concanavalin A specificity for oligosaccharides.

Crystal structure of uncleaved ovalbumin at 1.95 A resolution.

Structural studies of two ovalbumin glycopeptides in relation to the endo-beta-N-acetylglucosaminidase specificity.

The substrate specificities of endo-β-N-acetylglucosaminidases CII and H

A series of partially O-methylated N-methylglucosamines was synthesized by limited-time methylation of methyl-2-N-methylacetamido-2-deoxyglucopyranoside by Kuhn's procedure, followed by acid hydrolysis. These partially O-methylated N-methylglucosamines were separated satisfactorily by gas chromatography on a column of OV-17 on Gas-chrom Q as amino alditol acetates and identified from their mass spectra. For specific analysis of the methylated aminosugar derivatives, a mass fragmentographic method was established. Methylated aminosugars can be successfully determined in amounts as low as about 1 ng by this method.

Tadashi Tai

Papers

The substrate specificities of endo-β-N-acetylglucosaminidases CII and H

Synthesis and mass fragmentographic analysis of partially O-methylated 2-N-methylglucosamines.

Asparagine-linked oligosaccharide chains of IgG: a revised structure.

Differences in Substrate Specificities of endo-β-N-Acetylglucosaminidases CII and H