Catalytic efficiency of dehaloperoxidase A is controlled by electrostatics--application of the vibrational Stark effect to understand enzyme kinetics.
Catalytic efficiency of dehaloperoxidase A is controlled by electrostatics--application of the vibrational Stark effect to understand enzyme kinetics.
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DOI：
10.1016/j.bbrc.2012.12.047
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发表时间：
2013-01
影响因子：
3.1
通讯作者：
G. Schkolnik;T. Utesch;Junjie Zhao;Shu Jiang;M. Thompson;M. Mroginski;P. Hildebrandt;S. Franzen
中科院分区：
文献类型：
--
作者：
G. Schkolnik;T. Utesch;Junjie Zhao;Shu Jiang;M. Thompson;M. Mroginski;P. Hildebrandt;S. Franzen
振动斯塔克效应作为一种探测蛋白质电场的方法越来越受欢迎。在这项工作中，我们用它来解释的影响，单电荷突变的脱卤过氧化物酶-血红蛋白A（DHPA）的酶的动力学。在该杂志上发表的先前通信（BBRC 2012，420，733-737）中，已经表明通过突变增加DHP A的总负电荷导致其催化效率降低。在这里，通过标记的蛋白质与4-巯基苯甲腈（MBN），斯塔克探针分子，我们提供了进一步的证据表明，扩散控制的催化过程中产生的酶和带负电荷的基板之间的静电排斥。在蛋白质结合的MBN的腈伸缩频率和酶的单位点突变体的催化效率之间观察到的线性相关性表明静电相互作用在确定DHPA的催化效率中起主导作用。
The vibrational Stark effect is gaining popularity as a method for probing electric fields in proteins. In this work, we employ it to explain the effect of single charge mutations in dehaloperoxidase-hemoglobin A (DHP A) on the kinetics of the enzyme. In a previous communication published in this journal (BBRC 2012, 420, 733–737) it has been shown that an increase in the overall negative charge of DHP A through mutation causes a decrease in its catalytic efficiency. Here, by labeling the protein with 4-mercaptobenzonitrile (MBN), a Stark probe molecule, we provide further evidence that the diffusion control of the catalytic process arises from the electrostatic repulsion between the enzyme and the negatively charged substrate. The linear correlation observed between the nitrile stretching frequency of the protein-bound MBN and the catalytic efficiency of the single-site mutants of the enzyme indicates that electrostatic interactions play a dominant role in determining the catalytic efficiency of DHP A.