Stuart R A, Neupert W
Institut für Physiologische Chemie der Universität München, FRG.
Biochimie. 1990 Feb-Mar;72(2-3):115-21. doi: 10.1016/0300-9084(90)90136-5.
The cytochrome c import pathway differs markedly from the general route taken by the majority of other imported proteins, which is characterized by the import involvement of namely, surface receptors, the general insertion protein (GIP), contact sites and by the requirement of a membrane potential (delta psi). Unique features of both the cytochrome c precursor (apocytochrome c) and of the mechanism that transports it into mitochondria, have contributed to the evolution of a distinct import pathway that is not shared by any other mitochondrial protein analysed thus far. The cytochrome c pathway is particularly unique because i) apocytochrome c appears to have spontaneous membrane insertion-activity; ii) cytochrome c heme lyase seems to act as a specific binding site in lieu of a surface receptor and; iii) covalent heme addition and the associated refolding of the polypeptide appears to provide the free energy for the translocation of the cytochrome c polypeptide across the outer mitochondrial membrane.
细胞色素c的导入途径与大多数其他导入蛋白所采用的一般途径明显不同，后者的特征是涉及表面受体、通用插入蛋白（GIP）、接触位点，并且需要膜电位（Δψ）。细胞色素c前体（脱辅基细胞色素c）及其转运到线粒体中的机制的独特特征，促成了一种独特导入途径的进化，到目前为止分析的任何其他线粒体蛋白都不具有这种途径。细胞色素c途径特别独特，因为：i）脱辅基细胞色素c似乎具有自发的膜插入活性；ii）细胞色素c血红素裂合酶似乎作为特定的结合位点替代表面受体；iii）共价血红素添加和多肽的相关重折叠似乎为细胞色素c多肽跨线粒体外膜的转运提供了自由能。
