Degradation mechanism for Zearalenone ring-cleavage by Zearalenone hydrolase RmZHD: A QM/MM study
Degradation mechanism for Zearalenone ring-cleavage by Zearalenone hydrolase RmZHD: A QM/MM study
复制标题
玉米赤霉烯酮水解酶 RmZHD 裂解玉米赤霉烯酮的降解机制：QM/MM 研究
DOI：
10.1016/j.scitotenv.2019.135897
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发表时间：
2020-03-20
影响因子：
9.8
通讯作者：
Wang, Wenxing
中科院分区：
文献类型：
--
作者：
Zhou, Jie;Zhu, Ledong;Wang, Wenxing
玉米赤霉烯酮（ZEN）作为一种内分泌干扰物对人类和环境的危害日益引起人们的关注。本研究采用量子力学/分子力学（QM/MM）方法在原子水平上研究ZEN水解酶（RmZHD）对ZEN的降解机理。降解过程涉及两个协调的反应途径，其中活性位点包含Ser-His-Glu三重态作为质子供体。在玻尔兹曼加权平均势垒为18.1和21.5 kcal/mol的情况下，该过程发生质子转移和亲核取代环开环形成羟基产物。非共价相互作用分析阐明了关键氨基酸与ZEN之间的氢键。通过对16个氨基酸的静电影响分析，提出了残基Asp34和His128作为未来设计RmZHD酶突变的可能突变靶点。深入研究RmZHD的蛋白环境可以提高内分泌干扰物的生物修复效率。(C) 2019年Elsevier B.V.出版
The danger of zearalenone (ZEN) as an endocrine disruptor to humans and the environment has aroused increasing attention. In this study, we implemented the quantummechanics/molecularmechanics (QM/MM) method to investigate the degradation mechanism of ZEN hydrolase (RmZHD) toward ZEN at the atomic level. The degradation process involves two concerted reaction pathways, where the active site contains a Ser-His-Glu triplet as a proton donor. With the Boltzmann-weighted average potential barriers of 18.1 and 21.5 kcal/mol, the process undergoes proton transfer and nucleophilic-substituted ring opening to form a hydroxyl product. Non-covalent interaction analyses elucidated hydrogen bonding between key amino acids with ZEN. The electrostatic influence analysis of 16 amino acids proposes residues Asp34 and His128 as the possible mutation target for future mutation design of enzyme RmZHD. An in-depth investigation of the protein environment of RmZHD can improve the bioremediation efficiency of endocrine disrupting chemicals. (C) 2019 Published by Elsevier B.V.