Department of Life Science, University of Hyogo, Hyogo, Japan.
Annu Rev Biophys. 2011;40:205-23. doi: 10.1146/annurev-biophys-042910-155341.
Cytochrome c oxidase (CcO), as the terminal oxidase of cellular respiration, coupled with a proton-pumping process, reduces molecular oxygen (O(2)) to water. This intriguing and highly organized chemical process represents one of the most critical aspects of cellular respiration. It employs transition metals (Fe and Cu) at the O(2) reduction site and has been considered one of the most challenging research subjects in life science. Extensive X-ray structural and mutational analyses have provided two different proposals with regard to the mechanism of proton pumping. One mechanism is based on bovine CcO and includes an independent pathway for the pumped protons. The second mechanistic proposal includes a common pathway for the pumped and chemical protons and is based upon bacterial CcO. Here, recent progress in experimental evaluations of these proposals is reviewed and strategies for improving our understanding of the mechanism of this physiologically important process are discussed.
细胞色素 c 氧化酶（CcO）作为细胞呼吸的末端氧化酶，与质子泵过程偶联，将分子氧（O2）还原为水。这个引人入胜且高度有序的化学过程是细胞呼吸的关键特征之一。它在 O2 还原位点使用过渡金属（Fe 和 Cu），并被认为是生命科学中最具挑战性的研究课题之一。广泛的 X 射线结构和突变分析为质子泵机制提供了两种不同的方案。一种机制基于牛 CcO，包括质子泵的独立途径。第二种机制性方案包括质子泵和化学质子的共同途径，基于细菌 CcO。本文综述了这些方案的实验评估的最新进展，并讨论了改善对这个生理重要过程的机制理解的策略。
