Purification and characterization of piceid-beta-D-glucosidase from Aspergillus oryzae

The piceid-beta-D-glucosidase that hydrolyzes the beta-D-glucopyranoside bond of piceid to release resveratrol was isolated from Aspergillus oryzae sp. 100 strain, and the enzyme was purified and characterized. The enzyme was purified to one spot in SDS polyacrylamide gel electrophoresis, and its molecular weight was about 77 kDa. The optimum temperature of the piceid-beta-D-glucosidase was 60 degrees C, and the optimum pH was 5.0. The piceid-beta-D-glucosidase was stable at less than 60 degrees C, and pH 4.0-5.0. Ca2+, Mg2+ and Zn2+ ions have no significant effect on enzyme activity, but Cu2+ ion inhibits enzyme activity strongly. The K-m value was 0.74 mM and the V m value was 323 nkat mg(-1) for piceid. (c) 2006 Elsevier Ltd. All rights reserved.