生物技术通报 ›› 2013, Vol. 0 ›› Issue (10): 153-159.

• 研究报告 • 上一篇    下一篇

地芽孢杆菌Geobacillus sp.GXS1α-淀粉酶的饱和突变及酶学性质研究

薛蓓1,裴建新2, 王治宾3, 罗章1,韦宇拓4   

  1. (1. 西藏农牧学院食品科学学院,林芝 860000 ;2. 广西科学院国家非粮生物质能源工程技术研究中心,南宁 530007 ;3. 成都蓉生药业有限责任公司,成都 610041 ;4. 广西大学微生物及植物遗传工程教育部重点实验室,南宁 530005)
  • 收稿日期:2013-03-21 修回日期:2013-10-15 出版日期:2013-10-14 发布日期:2013-10-15
  • 作者简介:薛蓓, 女, 硕士, 讲师, 研究方向: 食品微生物学及生物技术;E-mail :13658940092@163.com

Saturation Mutagenesis and the Enzyme Properties of the Alpha-Amylase from Geobacillus sp.

Xue Bei1,Pei Jianxin2, Wang Zhibin3, Luo Zhang1,Wei Yutuo4,   

  1. (1. Department of Food Science,Tibet Agricultural and Animal Husbandry College,Linzhi 860000 ;2. National Engineering Research Center for Non-food Biorefinery,Guangxi Academy of Science,Nanning 530007 ;3.Chengdu Rongsheng Pharmaceuticals Co.,Ltd,Chengdu 610041 ;4. Key Laboratory of Microbial and Plant Genetic Engineering of Ministry of Education, Guangxi University,Nanning 530005)
  • Received:2013-03-21 Revised:2013-10-15 Published:2013-10-14 Online:2013-10-15

摘要:

采用半理性设计方法,在网站Geno3D 上以PDB 数据库中B. stearothermophilus 麦芽糖淀粉酶(BSMA) 的三维结构为模板,对AMY(α-淀粉酶)进行三维结构同源建模(二者氨基酸的同源性为33%)。比较同源建模预测的3D 结构和模板BSMA 的3D 结构关键位点,在此基础上通过计算机辅助设计软件ProSa2003, 根据能量变化确定了AMY 三个饱和突变位点:D192 、E221 和D289 。利用兼并引物对AMY 的假定活性中心位点D192 、E221 和D289 的氨基酸分别进行饱和突变,定点(饱和)突变库筛选得到4 个有活力的突变子D192A 、E221N 、E221L 和D289L, 并对突变酶的酶学性质进行初步研究。

关键词: 地芽孢杆菌, α-淀粉酶, 酶学性质, 饱和突变 

Abstract:

In this study, manipulation of half rational design was performed. Firstly, the dimensional structure of AMY(alpha-amylase of Geobacillus sp. GXS1)was built via homology modeling by using a close-related(33% homology in sequence)maltogenic amylase(BSMA) from B. stearothermophilus as a template. Secondly, three amino acid positions at the active site of AMY(Asp192, Glu221 and Asp289)were selected by structural superposition onto AMY combined with energy calculation by the computer-aided design software ProSa2003. These three putative amino acids for the active site of AMY, Asp192, Glu221 and Asp289, were subjected to saturation mutagenesis using degenerate primers. Four mutants(Asp192Ala, Glu221Asn, Glu221Leu and Asp289Leu)were obtained from the saturation mutant library, and studied the enzymatic properties of mutation enzyme simply.

Key words: Geobacillus, Alpha-amylase, Characterization, Site-saturation mutagenesis