Purification and characterization of beta-glucosidase from Bacteroides JY-6, a human intestinal bacterium.
A beta-glucosidase (EC 3.2.1.21.) was purified 2500-fold from Bacteroides JY-6, an intestinal anaerobic bacterium of human. The specific activity of the homogeneously purified enzyme was 210 mumol/min/mg protein. The enzyme (M(r) 75kDa) was an monomer whose pI and optimal pH values were 4.6 and 5.5-6, respectively. The best substrates were p-nitrophenyl beta-D-glucopyranoside and natural beta-bound glucosides, such as prunin and poncirenin. Puerarin, which is a C-glycoside, was weakly effective. However, cellobiose, alpha-bound glycosides and rhamnoglucosides were not effective. The apparent Kms for prunin and p-nitrophenyl-beta-D-glucopyranoside were determined to be 0.08 and 0.19 mM, respectively. The enzyme was strongly inhibited by p-chloromercuriphenylsulfonic acid and reaction products such as p-nitrophenol and glucose.
Kim
D H
DH
College of Pharmacy, Kyung-Hee University, Seoul, Korea.
Sohng
I S
IS
Kobashi
K
K
Han
M J
MJ
D001426:Bacterial Proteins / Q000032:analysis; D001439:Bacteroides / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D005243:Feces / Q000382:microbiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007422:Intestines / Q000382:microbiology*; D007700:Kinetics; D008970:Molecular Weight; D013056:Spectrophotometry, Ultraviolet; D013379:Substrate Specificity; D001617:beta-Glucosidase / Q000032:analysis* / Q000302:isolation & purification / Q000378:metabolism
D001426:Bacterial Proteins; D001617:beta-Glucosidase