Atypical kinetic behavior of chloroperoxidase-mediated oxidative halogenation of polycyclic aromatic hydrocarbons
Atypical kinetic behavior of chloroperoxidase-mediated oxidative halogenation of polycyclic aromatic hydrocarbons
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DOI：
10.1016/j.abb.2008.09.003
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发表时间：
2008-12-01
影响因子：
3.9
通讯作者：
Torres, Eduardo
中科院分区：
文献类型：
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作者：
Aburto, Jorge;Correa-Basurto, Jose;Torres, Eduardo
我们发现了几种多环芳烃(PAHs)被烟曲霉菌氯过氧化物酶(CPO)氧化卤化的非典型动力学行为。这种行为类似于P450家族的一些成员同时识别其活性部位的几个底物分子的能力。事实上，荧光研究表明，多环芳烃在溶液中以单体和pi-pi二聚体的形式存在，它们与CPO在不同程度上相互作用。用荧光分光光度法测定了每一种多环芳烃的二聚离解常数。此外，对接研究还表明，CPO可能识别其活性部位的一个或两个底物分子。用不同的非杂原子多环芳烃的动力学模型解释了多环芳烃氧化卤化反应中CPO的非典型S型动力学行为。结果表明，本研究中CPO的实际底物是所有被评估的多环芳烃的pi-pi二聚体。(C)2008 Elsevier Inc.保留所有权利
We have identified an atypical kinetic behavior for the oxidative halogenation of several polycyclic aromatic hydrocarbons (PAHs) by chloroperoxidase (CPO) from Caldariomyces fumago. This behavior resembles the capacity of some members of the P450 family to simultaneously recognize several substrate molecules at their active sites. Indeed, fluorometric studies showed that PAHs exist in solution as monomers and pi-pi dimers that interact to different extents with CPO. The dissociation constants of dimerization were evaluated for every single PAH by spectrofluorometry. Furthermore, docking studies also suggest that CPO might recognize either one or two substrate molecules in its active site. The atypical sigmoidal kinetic behavior of CPO in the oxidative halogenation of PAHs is explained in terms of different kinetic models for non-heteroatomic PAHs (naphthalene, anthracene and pyrene). The results suggest that the actual substrate for CPO in this study was the pi-pi dimer for all evaluated PAHs. (C) 2008 Elsevier Inc. All rights reserved