Energy conversion, redox catalysis and generation of reactive oxygen species by respiratory complex I.
Energy conversion, redox catalysis and generation of reactive oxygen species by respiratory complex I.
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DOI：
10.1016/j.bbabio.2015.12.009
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发表时间：
2016-07
期刊：
影响因子：
--
通讯作者：
Roessler MM
中科院分区：
文献类型：
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作者：
Hirst J;Roessler MM
复合物I（NADH：泛醌氧化还原酶）对于哺乳动物线粒体中的呼吸是关键的。它氧化由克雷布斯三羧酸循环和脂肪酸的β-氧化产生的NADH，还原泛醌，并运输质子以促进质子动力穿过内膜。复合物I也是细胞氧化应激的重要贡献者。在复合物I中，NADH被黄素单核苷酸氧化，随后分子内电子沿铁硫簇链沿着转移，将电子和能量传递给结合的泛醌。在簇N2（链中的末端簇）处或在泛醌/泛醇的结合/还原/解离后，来自氧化还原过程的能量被捕获以引发通过复合物的长程能量转移并驱动质子易位。这篇评论的重点是目前的知识，如何氧化还原反应和质子转移耦合，特别强调半醌中间体的形成和作用，在能量转换和活性氧的生产。本文是Volker Zickermann和Ulrich Brandt编辑的题为呼吸复合体I的特刊的一部分。综述了络合物Ⅰ催化氧化还原反应的研究进展。可能的醌还原途径。讨论了半醌中间体的存在和数量。团簇N2/semiquinones参与耦合质子转移进行了讨论。活性氧物质生产的半醌的证据进行检查。
Complex I (NADH:ubiquinone oxidoreductase) is critical for respiration in mammalian mitochondria. It oxidizes NADH produced by the Krebs' tricarboxylic acid cycle and β-oxidation of fatty acids, reduces ubiquinone, and transports protons to contribute to the proton-motive force across the inner membrane. Complex I is also a significant contributor to cellular oxidative stress. In complex I, NADH oxidation by a flavin mononucleotide, followed by intramolecular electron transfer along a chain of iron–sulfur clusters, delivers electrons and energy to bound ubiquinone. Either at cluster N2 (the terminal cluster in the chain) or upon the binding/reduction/dissociation of ubiquinone/ubiquinol, energy from the redox process is captured to initiate long-range energy transfer through the complex and drive proton translocation. This review focuses on current knowledge of how the redox reaction and proton transfer are coupled, with particular emphasis on the formation and role of semiquinone intermediates in both energy transduction and reactive oxygen species production. This article is part of a Special Issue entitled Respiratory complex I, edited by Volker Zickermann and Ulrich Brandt. Current knowledge of the redox reactions catalyzed by complex I is reviewed. Possible quinone reduction pathways are presented. The presence and number of semiquinone intermediates are deliberated. The involvement of cluster N2/semiquinones in coupled proton transfer is discussed. Evidence for reactive oxygen species production by semiquinones is examined.