β-glucosidase isolated from soybean okara shows specificity toward glucosyl isoflavones
Journal
Journal of Agricultural and Food Chemistry
Journal Volume
58
Journal Volume
58
Journal Issue
15
Journal Issue
15
Pages
8872-8878
Start Page
8872
End Page
8878
ISSN
15205118
Date Issued
2010-08-11
Author(s)
Abstract
A novel beta-glucosidase was isolated from soybean okara in this study. Along with the beta-glucosidase, a considerable basic 7S globulin of soybean was obtained in the initial extraction products. The protein samples pretreated with 130 mM dithiothreitol before the step of CM-Sepharose chromatography could greatly enhance the separation of the targeted beta-glucosidase from the impurities. The purified beta-glucosidase was found to be a monomer estimated to be 75 kDa by SDS-PAGE. The optimal temperature and pH for this beta-glucosidase were 45 degrees C and 4.5, respectively. The activity of this purified beta-glucosidase was completely inhibited by 1 mM Hg(2+) or 10 mM Al(3+) ion, and glucose and mannose also affected the activity. This beta-glucosidase possessed strict specificity toward glucosyl isoflavones but not malonylglucosidic conjugates of isoflavones of soybean. The N-terminal amino acid sequence of the beta-glucosidase was EYLKYKDPKA-, which highly matched that of glycosidases in maize (Zea mays) and wheat (Triticum asetivum).
Subjects
β-Glucosidase
dithiothreitol
okara
soybean isoflavones
SDGs
Type
journal article