POSSIBLE MOLECULAR MECHANISMS OF PROTONMOTIVE FUNCTION OF CYTOCHROME SYSTEMS
POSSIBLE MOLECULAR MECHANISMS OF PROTONMOTIVE FUNCTION OF CYTOCHROME SYSTEMS
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DOI：
10.1016/0022-5193(76)90124-7
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发表时间：
1976-01-01
影响因子：
2
通讯作者：
MITCHELL, P
中科院分区：
文献类型：
--
作者：
MITCHELL, P
一个概念框架适合探索和解释质子动力细胞色素系统的机制。经典的线粒体细胞色素系统的动力学和平衡行为的一些知识的回顾表明，简单的氧化还原回路的概念是不足以建立一个现实的概念模型。特别是，细胞色素b-c1复合物的组分的显着行为，这一直被认为是令人费解的，不能解释简单的氧化还原回路配方的基础上。新引入的质子动力泛醌循环或Q循环的概念，和循环回路2-3系统，代表了氧化还原回路概念的发展，为发展一个令人满意的理论提供了一个有希望的基础。Q循环的机制进行了讨论，并根据经典的线粒体细胞色素系统的实验知识。在叶绿体和细菌的Q循环的可能操作进行了简要讨论，并提请注意细菌细胞色素系统，似乎是组织作为简单的氧化还原循环，而不是作为循环系统。直接化学渗透耦合和间接构象耦合的概念的某些方面进行了比较的背景下，研究策略。[利用脉孢菌属、大肠杆菌、红球藻、R. capsulata和牛心线粒体进行了讨论。
A conceptual framework suitable for exploring and explaining the mechanisms of protonmotive cytochrome systems is evolved. A review of some of the knowledge of the kinetic and equilibrium behavior of the classical cytochrome systems of mitochondria indicates that the simple redox loop concept is not adequate for building a realistic conceptual model. In particular, the remarkable behavior of the components of the cytochrome b-c1 complex, which has long been regarded as puzzling, cannot be explained on the basis of simple redox loop formulations. The newly introduced concepts of the protonmotive ubiquinone cycle, or Q cycle, and of the cyclic loop 2-3 system, which represent developments of the redox loop concept, provide a promising basis for the evolution of a satisfactory theory. The mechanism of the Q cycle is discussed and developed in the light of experimental knowledge of classical mitochondrial cytochrome systems. The possible operation of a Q cycle in chloroplasts and bacteria is briefly discussed, and attention is drawn to bacterial cytochrome systems that appear to be organized as simple redox loops rather than as cyclic systems. Some aspects of notions of direct chemiosmotic coupling and indirect conformational coupling are compared in the context of research strategy. [Studies using Neurospora, Escherichia coli, Rhodopseudomonas spheroides, R. capsulata and bovine heart mitochondria are discussed.].