Binding modes of DL-2-haloacid dehalogenase revealed by crystallography, modeling and isotope effects studies
Binding modes of DL-2-haloacid dehalogenase revealed by crystallography, modeling and isotope effects studies
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DOI：
10.1016/j.abb.2013.09.012
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发表时间：
2013-12-01
影响因子：
3.9
通讯作者：
Paneth, Piotr
中科院分区：
文献类型：
--
作者：
Siwek, Agata;Omi, Rie;Paneth, Piotr
在酶中可以发现几种生物脱氯途径，每种途径都具有不同的氯同位素分异特征，因此可以作为特定机制的标志。与其他脱卤酶不同，dl -2-卤酸脱卤酶DL-DEX可以转化底物的两种对映体。这种酶的氯同位素效应比其他脱卤酶大。最近，这种酶的三维结构变得可用，使我们能够模拟这些同位素效应并寻找它们的起源。研究表明，氯动力学同位素效应的升高部分源于脱卤步骤之前酶活性位点内的结合和迁移过程。(C) 2013爱思唯尔公司版权所有。
Several pathways of biotic dechlorination can be found in enzymes, each characterized by different chlorine isotopic fractionation, which can thus serve as a signature of a particular mechanism. Unlike other dehalogenases, DL-2-haloacid dehalogenase, DL-DEX, converts both enantiomers of the substrate. Chlorine isotope effects for this enzyme are larger than in the case of other dehalogenases. Recently, the 3D structure of this enzyme became available and enabled us to model these isotope effects and seek their origin. We show that the elevated values of the chlorine kinetic isotope effects originate in part in the processes of binding and migration within the enzyme active site that precede the dehalogenation step. (C) 2013 Elsevier Inc. All rights reserved.