Fry M, Green D E
Proc Natl Acad Sci U S A. 1980 Nov;77(11):6391-5. doi: 10.1073/pnas.77.11.6391.
Cytochrome oxidase (ferrocytochrome c:oxygen oxidoreductase, EC 1.9.3.1) couples the aerobic oxidation of ferrocytochrome c to the cyclical transport of monovalent cations or to the active transport of monovalent and divalent cations. This transport capability is mediated by an intracomplex ion-transport chain of two protein-bound molecules of cardiolipin per molecule of cytochrome oxidase. Cardiolipin in a two-phase system shows the identical ionophoric pattern as does the cytochrome oxidase coupled system. A molecular model of the cardiolipin chain suggests the possibility of a cage-like structure through which cations can be transferred from phosphate group to phosphate group. The ion-transport chain and the electron-transport chain are anchored to the same set of subunits (I+IV); the close proximity of the two chains argues for the direct coupling of electron and cation flow. The ion-transport chain of cytochrome oxidase provides an introduction to the molecular mechanisms by which ions are moved across membranes in energy-coupling systems.
细胞色素氧化酶（亚铁细胞色素c：氧氧化还原酶，EC 1.9.3.1）将亚铁细胞色素c的需氧氧化与单价阳离子的循环转运或单价和二价阳离子的主动转运偶联起来。这种转运能力由每分子细胞色素氧化酶中两个与蛋白质结合的心磷脂分子组成的复合体内离子转运链介导。在两相系统中的心磷脂显示出与细胞色素氧化酶偶联系统相同的离子载体模式。心磷脂链的分子模型表明存在一种笼状结构的可能性，阳离子可通过该结构从磷酸基团转移至磷酸基团。离子转运链和电子转运链锚定在同一组亚基（I + IV）上；两条链的紧密相邻表明电子流和阳离子流直接偶联。细胞色素氧化酶的离子转运链为能量偶联系统中离子跨膜移动的分子机制提供了一个入门介绍。
