title: Monitoring the hydrolysis and transglycosylation activity of alpha-glucosidase from Aspergillus niger by nuclear magnetic resonance spectroscopy and mass spectrometry.
abstract: Alpha-glucosidase from Aspergillus niger is an enzyme that catalyzes hydrolysis of alpha-1,4 linkages and transglucosylation to form alpha-1,6 linkages. In this study, an analytical method of oligosaccharides by nuclear magnetic resonance (NMR) was used to provide quantitative estimation of the fractions of each sugar unit and was applied to characterize the alpha-glucosidase reaction. Our data indicated that alpha-glucosidase reacts with the nonreducing end of oligosaccharides to form an alpha-1,6 linkage, and then a sugar unit with two alpha-1,6 linkages is gradually produced. Data from mass spectrometry suggested that the sugar unit with two alpha-1,6 linkages originates mainly from a 3mer and/or 4mer when oligosaccharides are used as substrates.
authors.affiliation: Institute of Life Sciences, Ajinomoto Company, Kawasaki-ku, Kawasaki-shi 210-8681, Japan.
authors.forename: Nobuhisa
authors.initials: N
authors.lastname: Shimba
authors.forename: Mai
authors.initials: M
authors.lastname: Shinagawa
authors.forename: Wataru
authors.initials: W
authors.lastname: Hoshino
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Yamaguchi
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Yamada
authors.forename: Ei-ichiro
authors.initials: E
authors.lastname: Suzuki
mesh_terms: D001234:Aspergillus niger / Q000201:enzymology*; D002241:Carbohydrates / Q000032:analysis / Q000737:chemistry; D006031:Glycosylation; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D015394:Molecular Structure; D000520:alpha-Glucosidases / Q000032:analysis* / Q000378:metabolism*
chemical_list: D002241:Carbohydrates; D000520:alpha-Glucosidases