title: Substrate specificity of N-acetylhexosaminidase from Aspergillus oryzae to artificial glycosyl acceptors having various substituents at the reducing ends.
abstract: The substrate specificity of N-acetylhexosaminidase (E.C. 3.2.1.51) from Aspergillus oryzae was examined using p-nitrophenyl 6-O-sulfo-N-acetyl-beta-D-glucosaminide (6-O-sulfo-GlcNAc-O-pNP) as the glycosyl donor and a series of beta-d-glucopyranosides and N-acetyl-beta-D-glucosaminides with variable aglycons at the anomeric positions as the acceptors. When beta-D-glucopyranosides with methyl (CH(3)), allyl (CH(2)CHCH(2)), and phenyl (C(6)H(5)) groups at the reducing end were used as the acceptors, this enzyme transferred the 6-O-sulfo-GlcNAc moiety in the donor to the location of O-4 in these glycosyl acceptors with a high regioselectivity, producing the corresponding 6-O-sulfo-N-acetylglucosaminyl beta-D-glucopyranosides. However, beta-D-glucopyranose lacking aglycon was a poor substrate for transglycosylation. This A. oryzae enzyme could also accept various N-acetyl-beta-D-glucosaminides carrying hydroxyl (OH), methyl (CH(3)), propyl (CH(2)CH(2)CH(3)), allyl (CH(2)CHCH(2)) and p-nitrophenyl (pNP; C(6)H(4)-NO(2)) groups at their aglycons, yielding 6-O-sulfo-N-acetylglucosaminyl-beta(1-->4)-disaccharide products.
authors.affiliation: Science of Biological Resource, The United Graduate School of Agricultural Science, Gifu University, Yanagido 1-1, Gifu 501-1193, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Ogata
authors.forename: Xiaoxiong
authors.initials: X
authors.lastname: Zeng
authors.forename: Taichi
authors.initials: T
authors.lastname: Usui
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Uzawa
mesh_terms: D001236:Aspergillus oryzae / Q000201:enzymology*; D002236:Carbohydrate Conformation; D004187:Disaccharides / Q000138:chemical synthesis / Q000378:metabolism*; D005944:Glucosamine / Q000031:analogs & derivatives / Q000378:metabolism; D006031:Glycosylation; D008958:Models, Molecular; D015394:Molecular Structure; D013379:Substrate Specificity; D001619:beta-N-Acetylhexosaminidases / Q000378:metabolism*
chemical_list: D004187:Disaccharides; D001619:beta-N-Acetylhexosaminidases; D005944:Glucosamine