华南理工大学学报(自然科学版) ›› 2008, Vol. 36 ›› Issue (4): 122-126.

• 生物学 • 上一篇    下一篇

大肠杆菌MalQ基因的克隆与原核融合表达

王水兴郭勇许杨2   李燕萍2   

  1. 1. 华南理工大学 生物科学与工程学院, 广东 广州 510006; 2. 南昌大学 中德联合研究院, 江西 南昌 330047
  • 收稿日期:2007-03-07 修回日期:2007-04-19 出版日期:2008-04-25 发布日期:2008-04-25
  • 通信作者: 郭勇,教授,博士生导师. E-mail:feyguo@scut.edu.cn
  • 作者简介:王水兴(1965-),男,博士,南昌大学副教授,主要从事食品生物技术研究.E-mail:shuixingw@yahoo.com.cn.
  • 基金资助:

    广东省重点科技攻关项目(A301020201)

Cloning and Fusion Expression of Gene MalQ from E. coil

Wang Shui-xing1  Guo Yong1  Xu Yang2  Li Yan-ping2   

  1. 1. School of Biological Science and Engineering, South China University of Technology, Guangzhou, 510006, Guangdong, China; 2. Jiangxi-OAI Research Institute, Nanchang University, Nanchang, 330047, Jiangxi, China
  • Received:2007-03-07 Revised:2007-04-19 Online:2008-04-25 Published:2008-04-25
  • Contact: 郭勇,教授,博士生导师. E-mail:feyguo@scut.edu.cn
  • About author:王水兴(1965-),男,博士,南昌大学副教授,主要从事食品生物技术研究.E-mail:shuixingw@yahoo.com.cn.
  • Supported by:

    广东省重点科技攻关项目(A301020201)

摘要: 为了构建用于表达麦芽糖转糖基酶的基因工程菌,用PCR方法获得大肠杆菌(Escherichia coli)K12MalQ基因.将该基因插入原核表达载体pET-DsbA中,对质粒所含外源片段进行双向测序,并经局部相似性基本查询工具(BLAST)比较分析,发现其与GenBank中报道的大肠杆菌K12MalQ基因的同源性高达99%.重组质粒转化E.coliBL21(DE3)plysS,经异丙基硫代-β-D-半乳糖(IPTG)诱导后以融合蛋白形式表达,十二烷基硫酸钠-聚丙烯酰胺凝胶电泳显示MalQ基因与DsbA表达的融合蛋白在目标位置相对分子质量约为103 000处有明显条带.经薄层层析分析粗酶液酶处理的麦芽三糖溶液,证实粗酶液具有麦芽糖转糖基活性.

关键词: 麦芽糖转糖基酶, 基因重组, 融合表达, 大环糊精, 基因克隆

Abstract:

In order to construct a gene engineering bacterium expressing amylomaltase, gene MalQ was amplified from Escherichia coli K12 by PCR, and was cloned into pET-DsbA. Then, a two-direction sequencing was performed, and the results were analyzed by means of BLAST. There displayed high similarity (99%) of the obtained gene MalQ to the gene MalQ sequence of E. coli K12 reported in the GenBank. Moreover, the recombined plasmid pET-DsbA-MalQ was transformated into E. coli BL21 (DE3) plysS and was induced by IPTG. The fusion protein of gene MalQ and DsbA with a relative molecular mass of about 103000 was detected by means of sodium dodecyl sul- phate-polyacrylamide gel electrophoresis. 4-α-glucanotransferase activity of the crude enzyme was finally demonstrated by means of thin layer chromatography.

Key words: amylomahase, gene recombination, fusion expression, cycloamylose, gene clone