{"title":"Purification and characterization of exo-1,4-β-glucosidase from Acetobacter xylinum BPR2001","authors":"Naoki Tahara, Naoto Tonouchi, Hisato Yano, Fumihiro Yoshinaga","doi":"10.1016/S0922-338X(98)80010-X","DOIUrl":null,"url":null,"abstract":"<div><p>An exo-1,4-β-glucosidase (EC 3.2.1.74; G3ase) was obtained from the supernatant of cultured <em>Acetobacter xylinum</em> subsp. <em>sucrofermentans</em> BPR2001 and purified to homogeneity by ammonium sulfate precipitation, cation-exchange, gel-filtration and hydrophobic interaction chromatography. The enzyme migrated to a position corresponding to 81.2 kDa on SDS-polyacrylamide gel electrophoresis under both non-reducing and reducing conditions, suggesting that this enzyme is a monomer polypeptide. The isoelectric point was 6.0. N-Bromosuccinimide inhibited the activity of exo-1,4-β-glucosidase completely, whereas sulfhydryl reagents did not. The <em>K</em><sub>m</sub> and <em>V</em><sub>max</sub> for the hydrolysis of cellotriose as substrate were 3.7 mM and 7.4 μmol/min/mg, respectively. The enzyme specifically cleaved the non-reducing ends of β-glucosyl linkages of cellotriose or larger cello-oligosaccharides, 4-methylumberiferryl- and <em>p</em>-nitrophenyl-β-<span>d</span>-glucosides, but cellobiose was hydrolyzed only slightly and salicin not at all. The enzyme catalyzes the hydrolysis of glucosidic linkages in such a manner that the product retains the anomeric configuration of the substrate.</p></div>","PeriodicalId":15696,"journal":{"name":"Journal of Fermentation and Bioengineering","volume":"85 6","pages":"Pages 589-594"},"PeriodicalIF":0.0000,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0922-338X(98)80010-X","citationCount":"18","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Fermentation and Bioengineering","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0922338X9880010X","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 18
Abstract
An exo-1,4-β-glucosidase (EC 3.2.1.74; G3ase) was obtained from the supernatant of cultured Acetobacter xylinum subsp. sucrofermentans BPR2001 and purified to homogeneity by ammonium sulfate precipitation, cation-exchange, gel-filtration and hydrophobic interaction chromatography. The enzyme migrated to a position corresponding to 81.2 kDa on SDS-polyacrylamide gel electrophoresis under both non-reducing and reducing conditions, suggesting that this enzyme is a monomer polypeptide. The isoelectric point was 6.0. N-Bromosuccinimide inhibited the activity of exo-1,4-β-glucosidase completely, whereas sulfhydryl reagents did not. The Km and Vmax for the hydrolysis of cellotriose as substrate were 3.7 mM and 7.4 μmol/min/mg, respectively. The enzyme specifically cleaved the non-reducing ends of β-glucosyl linkages of cellotriose or larger cello-oligosaccharides, 4-methylumberiferryl- and p-nitrophenyl-β-d-glucosides, but cellobiose was hydrolyzed only slightly and salicin not at all. The enzyme catalyzes the hydrolysis of glucosidic linkages in such a manner that the product retains the anomeric configuration of the substrate.