title: Purification and characterization of ginsenoside Rb1-metabolizing beta-glucosidase from Fusobacterium K-60, a human intestinal anaerobic bacterium.
abstract: Fusobacterium K-60, a ginsenoside Rb1-metabolizing bacterium, was isolated from human intestinal feces. From this Fusodobacterium K-60, a ginsenoside Rb1-metabolizing enzyme, beta-glucosidase, has been purified. The enzyme was purified to apparent homogeneity by a combination of butyl-Toyopearl, hydroxyapatite ultragel, Q-Sepharose, and Sephacryl S-300 HR column chromatographies with a final specific activity of 1.52 micromol/min/mg. It had optimal activity at pH 7.0 and 40 degrees C. The molecular mass of this purified enzyme was 320 kDa, with 4 identical subunits (80 kDa). The purified enzyme activity was inhibited by Ba++, Fe++, and some agents that modify cysteine residues. This enzyme strongly hydrolyzed sophorose, followed by p-nitrophenyl beta-D-glucopyranoside, esculin, and ginsenoside Rb1. However, this enzyme did not change 20-O-beta-D-glucopyranosyl-20(S)-protopanaxadiol (IH-901) to 20(S)-protopanaxadiol, while it weakly changed ginsenoside Rb1 to IH-901. These findings suggest that the Fusobacterial beta-glucosidase is a novel enzyme transforming ginsenoside Rb1.
authors: College of Pharmacy, Kyung Hee University, Dongdaemun-ku, Seoul, Korea.
authors: S Y
authors: SY
authors: Park
authors: E A
authors: EA
authors: Bae
authors: J H
authors: JH
authors: Sung
authors: S K
authors: SK
authors: Lee
authors: D H
authors: DH
authors: Kim
mesh_terms: D005673:Fusobacterium / Q000201:enzymology*; D036145:Ginsenosides; D006801:Humans; D006868:Hydrolysis; D007422:Intestines / Q000382:microbiology*; D012503:Saponins / Q000378:metabolism*; D013379:Substrate Specificity; D001617:beta-Glucosidase / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D036145:Ginsenosides; D012503:Saponins; D001617:beta-Glucosidase