硫酯酶释放PKS产物过程中环化和水解竞争机制研究
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- 英文论文题名：Cyclization or hydrolysis?Pre-reaction states of thioesterase in erythromycin biosynthesis
- 论文作者：赵一雷 ; 石婷
- 英文论文作者：Yi-Lei Zhao ; Ting Shi ; College of Life Sciences and Biotechnology ; Shanghai Jiao Tong University ; State Key Laboratory of Microbial Metabolism ; Joint International Research Laboratory of Metabolic & Developmental Sciences
- 年：2016
- 作者机构：上海交通大学生命科学技术学院;微生物代谢国家重点实验室;
- 论文关键词：硫酯酶 ; 竞争反应 ; 预反应态
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第十九分会：化学中的量子与经典动力学
- 语种：中文
- 分类号：Q55
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第十九分会 ; 化学中的量子与经典动力学
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：2
- 文件大小：242k
- 原文格式：D
- 会议级别：全国
摘要
微生物通过PKS合成酶系生成种类丰富的大环内酯药物,然而异源硫酯酶催化非天然底物时常常发生水解副反应。我们以Erythromycin的硫酯酶DEBS为例,利用两个结构高度相似的探针分子(分别为化合物1和化合物2),研究其竞争机制中决定性因数。通过对两个系统的分子动力学模拟和QM/MM理论计算,发现DEBS反应活性口袋中Ala77、Leu146、Val170、Leu186、Leu190形成一个典型的疏水环境。该疏水口袋能够控制探针分子1的构象分布,使之形成一个环化反应的预反应状态。相对而言,探针分子2在该疏水口袋的优势构象是一个水解反应的预反应状态。虽然环化和水解的化学键断裂和形成数目和类型相同、反应活化能相近,然而不同的预反应状态却能够控制DEBS酶催化反应途径的bifurcation竞争性问题。另一方面,DEBS的天然底物更容易形成环化反应的预反应状态。预反应状态-底物适配关联性为生物合成基因工程提供了一个较高效的理性设计策略,在基因工程中可以用于控制硫酯酶的环化和水解反应途径占比和目标产物产量和选择性。
Microbial PKS synthase generates many macrocyclic polyketide drugs; however, thioesterase leads to unwanted hydrolysis in presence of "non-natural" substrate. Here we choose DEBS in Erythromycin biosynthesis as an example, investigating the competitive pathway based on two probe molecules(compounds 1 and 2 respectively). Using molecular dynamics simulation and QM / MM calculations, we found that Ala77, Leu146, Val170, Leu186, Leu190 can form a typical hydrophobic environment as enzyme reactive pocket. This hydrophobic pocket can control conformational distribution of the probe molecule 1, leading to a pre-reaction state for cyclization. In contrast, probe compound 2 would form a pre-reaction state for hydrolysis. Although chemical bond breaking and forming are identical in both cyclization and hydrolysis, pre-reaction state would determine the dominant product. Furthermore, the natural substrate results in cyclization pre-reaction state as well. Pre reaction state / substrate adaptation relationship(PRSA) provide an efficient rational design strategy for gene engineering in biological synthesis.
Microbial PKS synthase generates many macrocyclic polyketide drugs; however, thioesterase leads to unwanted hydrolysis in presence of "non-natural" substrate. Here we choose DEBS in Erythromycin biosynthesis as an example, investigating the competitive pathway based on two probe molecules(compounds 1 and 2 respectively). Using molecular dynamics simulation and QM / MM calculations, we found that Ala77, Leu146, Val170, Leu186, Leu190 can form a typical hydrophobic environment as enzyme reactive pocket. This hydrophobic pocket can control conformational distribution of the probe molecule 1, leading to a pre-reaction state for cyclization. In contrast, probe compound 2 would form a pre-reaction state for hydrolysis. Although chemical bond breaking and forming are identical in both cyclization and hydrolysis, pre-reaction state would determine the dominant product. Furthermore, the natural substrate results in cyclization pre-reaction state as well. Pre reaction state / substrate adaptation relationship(PRSA) provide an efficient rational design strategy for gene engineering in biological synthesis.
引文
[1]Chen,X.-P.;Zhao,Y.-L.*et al.ACS Catalysis.(under revision)
[2]Liu,F.;Zhao,Y.-L.;Zhang,X.-H.*et al.PLos ONE 2015,10(9):e0139081
[2]Liu,F.;Zhao,Y.-L.;Zhang,X.-H.*et al.PLos ONE 2015,10(9):e0139081