甲基对硫磷水解酶的随机突变和分子对接模拟  

Random mutation and molecular docking simulation of methyl parathion hydrolyse

作　　者：李亚楠[1] 张彦博[1] 胡美英[1] 陈少华[1] 胡振[1] 易欣[1] 林惠花[1] 

机构地区：[1]华南农业大学昆虫毒理研究室/天然农药与化学生物学教育部重点实验室,广州510642

出　　处：《华中农业大学学报》2012年第3期325-331,共7页Journal of Huazhong Agricultural University

基　　金：国家自然科学基金项目(30871660);广东省博士启动基金项目(9451064201003679)

摘　　要：甲基对硫磷水解酶(MPH)能高效降解甲基对硫磷,并能够降解杀螟松、乙基对硫磷和毒死蜱,但降解效率依次降低。为提高MPH对毒死蜱的降解活性,采用易错PCR的方法对MPH进行随机突变,筛选到2株突变体A291V和K173R,并对其进行原核表达,结果表明K173R对毒死蜱的降解活性比MPH提高了41.55%。通过同源建模及与毒死蜱的分子对接对酶的结构和功能进行初步分析,结果发现氨基酸残基R72在酶与毒死蜱的结合中起着重要作用。结合口袋和关键氨基酸的变化可最终导致K173R酶活性的提高。Methyl parathion hydrolyse（MPH） could degrade methyl parathion efficiently,as well as fenitrothion,ethyl parathion and chlorpyrifos,with the degradation efficiency decreasing systematically.In order to improve the degradation activity of MPH on chlorpyrifos,random mutation was carried out by error-prone PCR.Two mutants A291V and K173R were screened and expressed in E.coli BL21（DE3）.The degradation activity of K173R on chlorpyrifos increased 41.55% as compared to MPH.Besides,homology modeling and molecular docking were used for preliminary analysis of the relationship between the enzymes＇ structure and function.The results showed that the residue R72 played an important role in combination with chlorpyrifos,and changes occurring in the binding pocket and key amino acids eventually led to the increased degradation efficiency of K173R.

关 键 词：甲基对硫磷水解酶 毒死蜱 随机突变 易错PCR 同源建模 分子对接 

分 类 号：S481.8[农业科学—农药学]