Hosler Jonathan P, Ferguson-Miller Shelagh, Mills Denise A
Department of Biochemistry, University of Mississippi Medical Center, Jackson, Mississippi 39216, USA.
Annu Rev Biochem. 2006;75:165-87. doi: 10.1146/annurev.biochem.75.062003.101730.
A series of metalloprotein complexes embedded in a mitochondrial or bacterial membrane utilize electron transfer reactions to pump protons across the membrane and create an electrochemical potential (DeltamuH+). Current understanding of the principles of electron-driven proton transfer is discussed, mainly with respect to the wealth of knowledge available from studies of cytochrome c oxidase. Structural, experimental, and theoretical evidence supports the model of long-distance proton transfer via hydrogen-bonded water chains in proteins as well as the basic concept that proton uptake and release in a redox-driven pump are driven by charge changes at the membrane-embedded centers. Key elements in the pumping mechanism may include bound water, carboxylates, and the heme propionates, arginines, and associated water above the hemes. There is evidence for an important role of subunit III and proton backflow, but the number and nature of gating mechanisms remain elusive, as does the mechanism of physiological control of efficiency.
一系列嵌入线粒体或细菌膜中的金属蛋白复合物利用电子转移反应将质子泵过膜，从而产生电化学势（ΔμH⁺）。本文主要结合细胞色素c氧化酶研究中丰富的知识，探讨了目前对电子驱动质子转移原理的理解。结构、实验和理论证据支持了通过蛋白质中氢键连接的水链进行长距离质子转移的模型，以及氧化还原驱动泵中质子摄取和释放由膜嵌入中心的电荷变化驱动这一基本概念。泵浦机制中的关键元素可能包括结合水、羧酸盐、血红素丙酸酯、精氨酸以及血红素上方的相关水。有证据表明亚基III和质子回流起着重要作用，但门控机制的数量和性质仍然难以捉摸，效率的生理控制机制也是如此。
