TETRACHLOROHYDROQUINONE DEHALOGENASE

这项研究计划涉及确定一种 酶，四氯氢醌（TCHQ）脱卤酶。这种酶起着 在五氯苯酚的生物降解过程中发挥关键作用， 两次连续还原脱卤反应置换两个氯 与氢。该反应包括谷胱甘肽缀合步骤， 是谷胱甘肽S-转移酶机制中的重要步骤 （商品和服务税）。GST是存在于许多生物体中的非常重要的酶， 解毒过程。TCHQ脱卤酶具有一定的序列同一性， 与GST的机械相似性。这项工作的具体目标是 确定TCHQ脱卤酶是否完成氯的去除 从TCHQ经由初始互变异构化随后进行S/N/2反应， 或通过亲核芳族取代反应， 通常在GST的芳香共轭反应中发现。 TCHQ脱卤酶将通过实验和理论测定 技术.实验和理论技术的使用是 这对全面了解TCHQ的机制非常重要 脱卤酶及其机制与GST的相似性。

This research proposal involves the determination of the mechanism of an enzyme, tetrachlorohydroquinone (TCHQ) dehalogenase. The enzyme plays a critical role in the biodegradation of pentachlorophenol, by performing two successive reductive dehalogenation reaction replacing two chlorines with hydrogens. The reaction includes a glutathione conjugation step which is an essential step in the mechanism of glutathione S-transferases (GSTs). GSTs are very important enzymes present in many organisms for detoxification processes. TCHQ dehalogenase has some sequence identity and mechanistic similarities to GSTs. The specific aim of this work is to determine whether TCHQ dehalogenase accomplishes the removal of a chlorine from TCHQ via an initial tautomerization to follow for an S/N/2 reaction, or via a nucleophilic aromatic substitution reaction such as those commonly found in aromatic conjugation reactions of GSTs.The mechanism of TCHQ dehalogenase will be determined by experimental and theoretical techniques. The use of both experimental and theoretical techniques is important to the overall understanding of the mechanism of TCHQ dehalogenase and how similar its mechanism is to that of GSTs.