title: Structures of sugar chains of the subunits of an alpha-amylase inhibitor from Phaseolus vulgaris white kidney beans.
abstract: The structures of asparagine-linked oligosaccharides in the subunits of an alpha-amylase inhibitor from the white kidney bean (Phaseolus vulgaris) were determined. Glycopeptides obtained from each subunit were treated with hydrazine, then N-acetylated. The oligosaccharides thus liberated were labeled with 2-aminopyridine at their reducing ends and purified by gel-permeation, reverse-phase, and size-fractionation HPLC. The structures of seven oligosaccharides from the alpha-subunit and eight oligosaccharides from the beta-subunit were determined by a combination of composition and molecular size analyses, exo- and endoglycosidase digestions, partial acetolysis, and 1H-NMR spectroscopy. The major glycan chains in the alpha-subunit were Man alpha 1-6(Man alpha 1-3)Man alpha 1-6(Man alpha 1-2Man alpha 1-3)-Man beta 1-4GlcNAc beta 1-4GlcNAc and (Man alpha 1-2)Man alpha 1-6(Man alpha 1-2Man alpha 1-3)Man alpha 1-6 (Man alpha 1-2Man alpha 1-2Man alpha 1-3)Man beta 1-4GlcNAc beta 1-4GlcNAc, while a glycan chain Man alpha 1-6(Man alpha 1-3)(Xyl beta 1-2)Man beta 1-4GlcNAc beta 1-4GlcNAc comprised more than 70% of the sugar moiety of the beta-subunit.
authors.affiliation: Department of Agricultural Chemistry, College of Agriculture, University of Osaka Prefecture.
authors.forename: H
authors.initials: H
authors.lastname: Yamaguchi
authors.forename: H
authors.initials: H
authors.lastname: Funaoka
authors.forename: H
authors.initials: H
authors.lastname: Iwamoto
mesh_terms: D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D007887:Fabaceae; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry*; D010946:Plants, Medicinal; D000516:alpha-Amylases / Q000037:antagonists & inhibitors*
chemical_list: D009844:Oligosaccharides; D000516:alpha-Amylases