生物技术通报 ›› 2015, Vol. 31 ›› Issue (1): 181-185.doi: 10.13560/j.cnki.biotech.bull.1985.2015.01.027

• 研究报告 • 上一篇    下一篇

敏捷食酸菌腈水解酶基因在大肠杆菌中的表达

管启旺 马江锋 贺爱永 姜岷 宫长斌   

  1. (南京工业大学生物与制药工程学院 材料与化学工程国家重点实验室,南京 211816)
  • 收稿日期:2014-06-12 出版日期:2015-01-09 发布日期:2015-01-10
  • 作者简介:管启旺,男,硕士,研究方向:工业微生物;E-mail:819468208@qq.com
  • 基金资助:
    国家自然科学基金项目(21076105),国家重点基础研究发展计划(“973”计划)(2009CB724701),江苏高校优势学科建设工程项目

Expression of Nitrilase Gene from Acidovorax facilis in Escherichia coli

Guan Qiwang, Ma Jiangfeng, He Aiyong, Jiang Min, Gong Changbin   

  1. (State Key Laboratory of Materials-Oriented Chemical Engineering,College of Biotechnology and Pharmaceutical Engineering,Nanjing Tech University,Nanjing 211816)
  • Received:2014-06-12 Published:2015-01-09 Online:2015-01-10

摘要: 以含有敏捷食酸菌的腈水解酶基因的克隆质粒为模板,通过PCR扩增获得长度为1 080 bp的腈水解酶(Nitrilase)基因片段。使用表达质粒pET-28-a构建表达载体,获得重组质粒pET-Nit。对所表达的基因进行测序对比发现与GenBank所公布的基因序列比较,相似性99%,读码框出现2 bp的突变,但并未引起相应氨基酸突变,故不影响酶的表达与特性。将重组质粒转化到表达宿主Escherichia coli Rosetta(DE3)感受态中,使用诱导剂IPTG对菌株进行诱导表达,获取菌液进行SDS-PAGE分析,得知目的蛋白分子量约为41.28 kD,与预期所想的一致。酶活力分析表明,上清的比活力为3 U/mg。进一步对诱导条件进行优化,包括诱导温度,IPTG浓度,诱导时间等一系列条件。在最优条件下,扩大培养体积,比活力可达15 U/mg,活力提高了5倍左右。

关键词: 腈水解酶, 敏捷食酸菌, 大肠杆菌, 克隆

Abstract: Plasmid containing Acidovorax facilis gene, was used as a template, and length of 1 080 bp nitrilase(Nitrilase)gene fragment was obtained by PCR. Expressed genes were sequenced and compared to gene sequences found in GenBank. There are 2 bp mutation was found, which can not affect the expression and characterization of the enzyme. The recombinant plasmid was transformed into the Escherichia coli Rosetta(DE3)competent cell, which was induced IPTG for strain- expression. SDS-PAGE analysis was used and showed that the protein molecular weight was about 41.28 kD. Enzyme activity analysis showed that the specific activity of the supernatant was 3 U/mg. Induction conditions were optimized, including induction temperature, IPTG concentration, induction time and a series of conditions. Under optimal conditions and with the expansion of the culture volume, the specific activity can up to 15 U/mg, and activity increased by about five times.

Key words: nitrilase, Acidovorax facilis, Escherichia coli, clone