title: A β-glucosidase from Novosphingobium sp. GX9 with high catalytic efficiency toward isoflavonoid glycoside hydrolysis and (+)-catechin transglycosylation.
abstract: In view of the important role of isoflavonoids and their related glycoconjugates in human health, there is considerable interest in their enzymatic conversion. SBGL, a novel β-glucosidase isolated from Novosphingobium sp. GX9, was expressed in Escherichia coli and found to have high activity for hydrolysis of daidzin and genistin. SBGL showed very low K m values for daidzin and genistin, and the k cat/K m values for these substrates were 33,300 and 19,200 s(-1) mM(-1), respectively. The SBGL glucosidase could also transglycosylate the flavanol (+)-catechin at saturating acceptor concentrations, which has not previously been reported for a β-glucosidase and is difficult to achieve synthetically.
authors.affiliation: The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi, 530005, China.
authors.forename: Liqin
authors.initials: L
authors.lastname: Du
authors.forename: Zilong
authors.initials: Z
authors.lastname: Wang
authors.forename: Yingli
authors.initials: Y
authors.lastname: Zhao
authors.forename: Jinqun
authors.initials: J
authors.lastname: Huang
authors.forename: Hao
authors.initials: H
authors.lastname: Pang
authors.forename: Yutuo
authors.initials: Y
authors.lastname: Wei
authors.forename: Lihua
authors.initials: L
authors.lastname: Lin
authors.forename: Ribo
authors.initials: R
authors.lastname: Huang
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D002392:Catechin / Q000378:metabolism*; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D015870:Gene Expression; D006031:Glycosylation; D006868:Hydrolysis; D007529:Isoflavones / Q000378:metabolism*; D007700:Kinetics; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D042301:Sphingomonadaceae / Q000201:enzymology*; D001617:beta-Glucosidase / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D007529:Isoflavones; C040641:genistin; C013908:daidzin; D002392:Catechin; D001617:beta-Glucosidase