ORGANIZATION AND CONTROL OF ELECTRON TRANSFER CHAINS

这项研究的目的是阐明蛋白质结构的要求， 线粒体电子转移链中的电子转移和控制，以及 在微粒体NADPH细胞色素c（P450）还原酶系统中。 拟 在细胞色素氧化酶的水平上控制氧消耗可以 涉及与血红蛋白定义的机制类似的机制，其中， 亚基之间的静电相互作用决定了氧的亲和力 在血红素处结合。 在细胞色素氧化酶的情况下，强离子 与其底物细胞色素c的相互作用可能会影响 氧化酶的构象，因为是膜电位梯度。 的影响 细胞色素c的存在，不存在和结合亲和力对呼吸系统的影响 将研究偶联线粒体内膜中的控制。 稳态， 反应的预稳态和低温动力学分析 天然和修饰的细胞色素c与细胞色素c氧化酶将进行 用纯化的单分散氧化酶制剂，以及用 膜结合形式，以进一步阐明的机制和力学， 反应。 这也需要进行直接的约束力研究， 研究共价交联细胞色素c的动力学效应 纯化和膜结合氧化酶。 细胞色素c与 微粒体NADPH-细胞色素c（P450）还原酶将作为 细胞色素c结构的功能、离子强度、细胞色素P450的存在， 和还原酶制剂的类型（蛋白酶溶解的、去污剂 溶解的和膜结合的），以确定蛋白质的性质 涉及的互动。

The aim of this research is to elucidate the protein structural requirements for electron transfer and control in the mitochondrial electron transfer chain, and in the microsomal NADPH cytochrome c (P450) reductase system. It is proposed that control of oxygen consumption at the level of cytochrome oxidase may involve a mechanism similar to that defined for hemoglobin, in which changes in electrostatic interactions between subunits determine the affinity of oxygen binding at the heme. In the case of cytochrome oxidase, the strong ionic interactions with its substrate, cytochrome c, are likely to influence the conformation of the oxidase, as is the membrane potential gradient. The effects of the presence, absence and binding affinity of cytochrome c on respiratory control in coupled inner mitochondrial membranes will be studied. Steady-state, pre-steady state, and low-temperature kinetic analyses of the reactions of native and modified cytochromes c with cytochrome c oxidase will be carried out with a purified, mono disperse oxidase preparation, as well as with the membrane-bound form, in order to further clarify the mechanism and mechanics of the reaction. This will also require direct binding studies and an investigation of the kinetic effects of covalently cross-linking cytochrome c to purified and membrane-bound oxidase. The reaction of cytochrome c with microsomal NADPH-cytochrome c (P450) reductase will be investigated as a function of cytochrome c structure, ionic strength, presence of cytochrome P450, and the type of reductase preparation (protease-solubilized, detergent solubilized, and membrane-bound), in order to define the nature of the protein interactions involved.