title: Galactosyl transfer onto p-nitrophenyl beta-D-glucoside using beta-D-galactosidase from Bacillus circulans.
abstract: beta-D-Gal-(1-->4)-beta-D-Glc-OC6H4NO2-p and its isomers (beta-D-Gal-(1-->3)-beta-D-Glc-OC6H4NO2-p and beta-D-Gal-(1-->6)-beta-D-Glc-OC6H4NO2-p) were synthesized from lactose and beta-D-Glc-OC6H4NO2-p, using transglycosylation by the beta-D-galactosidase from Bacillus circulans. This reaction was efficient enough for us to do a one-pot preparation of galactosyl-glucoside from lactose. The order of the production of the transfer products was (1-->4) > > (1-->3) > (1-->6) in the initial stage of the reaction, and the same relationship was observed for the hydrolytic rate toward the three galactosyl-glucosides. The production of (1-->4)- and (1-->3)-linkages greatly decreased during the subsequent reaction and much more of the (1-->6)- than of the (1-->4)- and (1-->3)-transfer products was found in the later stage of the reaction.
authors.affiliation: Faculty of Agriculture, Department of Applied Biological Chemistry, Shizuoka University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Murata
authors.forename: S
authors.initials: S
authors.lastname: Akimoto
authors.forename: M
authors.initials: M
authors.lastname: Horimoto
authors.forename: T
authors.initials: T
authors.lastname: Usui
mesh_terms: D001407:Bacillus / Q000201:enzymology*; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D004187:Disaccharides / Q000737:chemistry / Q000378:metabolism; D005690:Galactose / Q000737:chemistry / Q000378:metabolism*; D005960:Glucosides / Q000138:chemical synthesis* / Q000378:metabolism*; D006031:Glycosylation; D007536:Isomerism; D007785:Lactose / Q000737:chemistry / Q000378:metabolism; D008969:Molecular Sequence Data; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013379:Substrate Specificity; D001616:beta-Galactosidase / Q000737:chemistry / Q000378:metabolism*
chemical_list: D004187:Disaccharides; D005960:Glucosides; C025193:4-nitrophenyl beta-D-glucoside; D001616:beta-Galactosidase; D007785:Lactose; D005690:Galactose