文献类型：期刊文献

英文题名：Identification, purification and characterization of β-glucosidase from apple seed as a novel catalyst for synthesis of O-glucosides

作者：Yu, Hui-Lei; Xu, Jian-He; Lu, Wen-Ya; Lin, Guo-Qiang

机构：[1]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Lab Biocatalysis & Bioproc, Shanghai 200237, Peoples R China;[2]Chinese Acad Sci, Shanghai Inst Organ Chem, Shanghai 200032, Peoples R China

年份：2007

卷号：40

期号：2

起止页码：354

外文期刊名：ENZYME AND MICROBIAL TECHNOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000243603500025)】；

语种：英文

外文关键词：apple seed; characterization; beta-glucosidase; purification; thermal stability

摘要：Among several fruit seeds, apple seed was identified as a new promising beta-glucosidase source for alkyl O-glucoside synthesis by reverse hydrolysis, since it showed high hydrolytic activities on a broad spectrum of beta-glucosides. From the crude extract of apple seed meal, a major glucosidase isoenzyme was purified to homogeneity, with a purification factor of 47-fold and an overall yield of 12.8%, by ammonium sulfate fractionation and chromatographic separation through DEAE-Cellulose, Butyl-Toyopearl and Sephadex G150 columns. The purified enzyme is a homodimer; each subunit has a molecular mass of about 60 kDa as determined by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and the pI of this beta-glucosidase is about 5.7. These properties indicate that the apple seed beta-glucosidase is totally different from any of the almond beta-glucosidase isozymes reported so far. Furthermore, the purified enzyme of apple seed displays higher thermal stability than the commercially supplied beta-glucosidase from almond, with half-lives of 42.9h and 14.2h, respectively, as preserved at 50 degrees C in an aqueous environment. The optimum pH of the apple seed beta-glucosidase was 6.0 and the stable pH range was 5.0-9.0, both similar to those of the commercial almond beta-glucosidase. (c) 2006 Elsevier Inc. All rights reserved.