DBAT酶的同源建模及与多样性底物对接  

Homology modeling of 10-deacetylbaccatin Ⅲ-10β-O-acetyltransfer ase and its docking simulation of diversity substrates

作　　者：黄佳俊[1,2] 林淑玲 欧阳萍兰 魏韬 郑倩望 叶志伟 郭丽琼[1,2] 林俊芳 HUANG Jia-jun;LIN Shu-ling;OU YANG Ping-lan;WEI Tao;ZHENG Qian-wang;YE Zhi-wei;GUO Li-qiong;LIN Jun-fang(Department of Bioengineering,College of Food Science,South China Agricultural University,Guangzhou 510642,China;Research Center for Micro-Ecological Agent Engineering and Technology of Guangdong Province,Guangzhou 510642,China)

机构地区：[1]华南农业大学食品学院生物工程系,广东广州510642 [2]广东省微生态制剂工程技术研究中心,广东广州510642

出　　处：《化学研究与应用》2018年第8期1246-1251,共6页Chemical Research and Application

基　　金：广东省科技计划项目(2014B050505018;2015A020209121)资助;广州市科技计划项目(201607010197)资助;国家自然科学基金项目(31071837)资助

摘　　要：10-去乙酰巴卡亭Ⅲ乙酰基转移酶(DBAT)是紫杉醇生物合成途径中催化10-去乙酰巴卡亭Ⅲ生成巴卡亭Ⅲ的一个关键酶,由于其催化效率低,使得天然巴卡亭Ⅲ和紫杉醇含量都很低,紫杉醇细胞工厂的构建也受到严重制约。本研究利用MODELLER同源建模软件,构建了未报道晶体结构的DBAT三维结构模型,结合分子动力学模拟DBAT在稳定状态前后氨基酸的位置变化,分析关键氨基酸改变对酶催化活性的影响,获得位点His162和Arg365。利用虚拟定点突变和分子对接技术,推断His162为关键活性氨基酸残基,Arg365的空间位阻效应可影响催化反应过程。本研究为后续DBAT催化机理的解析提供潜在靶点,并为DBAT分子设计奠定基础。10-deacetylbaccatin III-10β-O-acetyltransferase(DBAT)was a key enzyme that catalyzes the synthesis of baccatin III in the biosynthetic pathway of paclitaxel.The contents of natural baccatin III and paclitaxel was very low since its catalytic efficiency was very inferior.Therefore,increasing the enzyme catalytic efficiency by means of protein engineering had become necessary for improving the yield of baccatin III for the chemical semi-synthesis of paclitaxel.However,the three-dimensional crystal structure of DBAT had not been resolved so far.In this study,the homology structure of DBAT using computer modeling based-on MODELLER was built and the model was refined.The molecular dynamics simulation was used to analyze the mutation positions of the amino acid residues in the enzyme.It found that His162 and Arg365 were the critical amino acid residues of the enzyme.The virtual site-directed mutagenesis and molecular docking results showed that His162 was the key active residue.Meanwhile,the steric hindrance of Arg365 played an important role in the catalytic reaction.This study provided insights into the catalytic mechanism of DBAT,as well as laid the foundation for the molecular design of DBAT.

关 键 词：紫杉醇 巴卡亭Ⅲ DBAT 同源建模 分子对接 活性口袋 

分 类 号：O643.1[理学—物理化学]