Could CuB be the site of redox linkage in cytochrome c oxidase?
نویسندگان
چکیده
This paper explores the proton pumping function of cytochrome c oxidase [ferrocytochrome-c:oxygen oxidoreductase (EC 1.9.3.1)] based upon redox linkage at the "high-potential" CuB center. A model is proposed that is derived from a redox-linked ligand exchange mechanism previously described for the CuA site. Qualitative analysis of this mechanism indicates that such a mechanism is feasible. However, the relatively short distance between CuB and cytochrome a3 implies that the uncoupling electron transfers are quite facile. In addition, the position of the CuB center with respect to the inner mitochondrial membrane argues against redox linkage at the CuB site.
منابع مشابه
Proton pumping in cytochrome c oxidase: the coupling between proton and electron gating.
C ytochrome c oxidase is the terminal oxidase in cellular respiration. This membrane protein accepts electrons from ferrocytochrome c in the periplasmic space of the mitochondrion, one electron at a time, and transfers the reducing equivalents to the binuclear heme-iron copper site (the socalled Fea3, CuB site), where dioxygen binds and the O·O bond is subsequently cleaved (1). In this manner, ...
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عنوان ژورنال:
- Proceedings of the National Academy of Sciences of the United States of America
دوره 89 2 شماره
صفحات -
تاریخ انتشار 1992