Sodium-translocating NADH:quinone oxidoreductase as a redox-driven ion pump
Sodium-translocating NADH:quinone oxidoreductase as a redox-driven ion pump
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DOI：
10.1016/j.bbabio.2009.12.020
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发表时间：
2010-06-01
影响因子：
4.3
通讯作者：
Bogachev, Alexander V.
中科院分区：
文献类型：
--
作者：
Verkhovsky, Michael I.;Bogachev, Alexander V.
Na+-转位的NADH：泛醌氧化还原酶（Na+-NQR）是多种细菌呼吸链的组成部分。这种酶是线粒体复合物I的类似但非同源的对应物。Na+-NQR驱动相同的化学反应，也使用释放的能量将离子转运穿过膜，但它泵送Na+而不是H+。钠泵的机制很可能与质子泵的机制完全不同（例如，它不能适应离子运动的Grotthuss机制）;这就是为什么酶的结构，亚基和辅基是完全特殊的。本文综述了细菌Na+转运NADH：醌氧化还原酶的结构和催化性质的现代知识。通过酶的辅因子和热力学性质的电子转移的顺序进行了讨论。的决议的中间体的催化循环和本地化的钠依赖性的步骤相结合，在一个可能的分子机制的钠转移的酶。(C)2010爱思唯尔有限公司版权所有。
The Na+-translocating NADH:ubiquinone oxidoreductase (Na+-NQR) is a component of the respiratory chain of various bacteria. This enzyme is an analogous but not homologous counterpart of mitochondrial Complex I. Na+-NQR drives the same chemistry and also uses released energy to translocate ions across the membrane, but it pumps Na+ instead of H+. Most likely the mechanism of sodium pumping is quite different from that of proton pumping (for example, it could not accommodate the Grotthuss mechanism of ion movement); this is why the enzyme structure, subunits and prosthetic groups are completely special. This review summarizes modem knowledge on the structural and catalytic properties of bacterial Na+-translocating NADH:quinone oxidoreductases. The sequence of electron transfer through the enzyme cofactors and thermodynamic properties of those cofactors is discussed. The resolution of the intermediates of the catalytic cycle and localization of sodium-dependent steps are combined in a possible molecular mechanism of sodium transfer by the enzyme. (C) 2010 Elsevier B.V. All rights reserved.