title: Purification and characterization of a novel and unique ginsenoside Rg1-hydrolyzing β-D-glucosidase from Penicillium sclerotiorum.
abstract: In this paper, a novel and unique ginsenoside Rg(1)-hydrolyzing β-D-glucosidase from Penicillium sclerotiorum was isolated, characterized, and generally described. The β-glucosidase is an ~180 kDa glycoprotein with pI 6.5, and consists of four identical subunits of ~40 kDa. The β-glucosidase was active in a narrow pH range (4-5) and at relatively high temperature (60-70°C). The optimal activity against p-nitrophenyl-β-D-glucopyranoside (pNPG) was as follows: pH 4.5 and temperature 65°C. Under these conditions, the K(m) of the enzyme was 0.715 mM with a V(max) of 0.243 mmol nitrophenol/min mg. Metal ions such as Ba(2+), K(+), Fe(3+), and Co(2+) significantly promoted the enzymatic activity, while Ca(2+), Mg(2+), and Ag(+) inhibited its activity. Of the tested substrates, only ginsenoside Rg(1) could be specifically hydrolyzed by the β-glucosidase at the C6-glucoside to form the rare ginsenoside F(1). These properties were novel and different from those of other previously described glycosidases.
authors.affiliation: School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wei
authors.forename: Wenqian
authors.initials: W
authors.lastname: Zhao
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Zhao
authors.forename: Yixuan
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D002412:Cations / Q000737:chemistry; D036145:Ginsenosides / Q000378:metabolism*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D008970:Molecular Weight; D010407:Penicillium / Q000201:enzymology*; D013379:Substrate Specificity; D001617:beta-Glucosidase / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D002412:Cations; D036145:Ginsenosides; C055327:ginsenoside F1; D001617:beta-Glucosidase; C035054:ginsenoside Rg1