化工进展2017，Vol.36Issue(3)：1041-1046,6.DOI:10.16085/j.issn.1000-6613.2017.03.036
解糖热纤维菌木糖苷酶的分离纯化及其酶学性质
Purification and characterization of a thermostableβ-xylosidase from Caldicellulosiruptor saccharolyticus
摘要
Abstract
The xylosidase from the anaerobic spore bacteriaCaldicellulosiruptor saccharolyticus (XYL39B),which hydrolyzes xylooligosaccharides to xyloses,was classified into the glycoside hydrolase family 2(GH2)by the bioinformatics analyses. The XYL39B gene (xyl39B) ression was transformed intoEscherichia coli BL21(DE3). The recombinant XYL39B was purified by heat treatment and the Ni-NTA chromatography. The purified XYL39B reached its maximum activity at 70℃ and pH 6.0; and it retained over 90% of its initial activity at 70℃ and pH 6.0 for 2 hours. The enzyme had a broad temperature optima,and it was quite stable at temperatures ranging from 55 to 75℃. The activities of XYL39B were significantly inhibited by Zn2+、Cu2+ and SDS. The XYL39B had aKm of 11.47mmol/L,aVmax of 29.40U/g,aKcat of 20.60s–1 and had an apparent activation energy(Ea)of 14.52kJ/mol forp-nitrophenyl-β-D-xyloside(pNPX). All results indicated that the recombinant enzyme was an extreme thermophilic bacterial xylosidase which exhibited efficient catalytic activities and highly tolerant to xylose inhibition(inhibition constantKi=306.87mmol/L). This work established a foundation for the subsequent modification and application of XYL39B.关键词
极端耐热/β-木糖苷酶/解糖热纤维菌/亲和层析/酶学性质Key words
thermostable/β-xylosidase/Caldicellulosiruptorsaccharolyticus/affinity chromatography/enzyme characterization分类
生物科学引用本文复制引用
王月皎,夏乾竣,周佩,张瑜,王飞,李迅..解糖热纤维菌木糖苷酶的分离纯化及其酶学性质[J].化工进展,2017,36(3):1041-1046,6.基金项目
国家林业局"948"项目(2014-4-37),国家自然科学基金(31270612,31370572)及江苏高校品牌专业建设工程项目(PPZY2015C22). （2014-4-37）
