The proton pump of cytochrome oxidase.
نویسنده
چکیده
منابع مشابه
Mutation of a single residue in the ba3 oxidase specifically impairs protonation of the pump site.
The ba3-type cytochrome c oxidase from Thermus thermophilus is a membrane-bound protein complex that couples electron transfer to O2 to proton translocation across the membrane. To elucidate the mechanism of the redox-driven proton pumping, we investigated the kinetics of electron and proton transfer in a structural variant of the ba3 oxidase where a putative "pump site" was modified by replace...
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The existence of a proton pump associated with bovine cytochrome c oxidase (EC 1.9.3.1) has over the last few years been a matter of considerable dispute. In an attempt to resolve some of the problems with the measuring system we have synthesized ffuoresceinphosphatidylethanolamine which when reconstituted with cytochrome c oxidase into phospholipid vesicles provided a reliable indicator of the...
متن کاملStructural Changes and Proton Transfer in Cytochrome c Oxidase
In cytochrome c oxidase electron transfer from cytochrome c to O2 is linked to transmembrane proton pumping, which contributes to maintaining a proton electrochemical gradient across the membrane. The mechanism by which cytochrome c oxidase couples the exergonic electron transfer to the endergonic proton translocation is not known, but it presumably involves local structural changes that contro...
متن کاملDirect measurement of proton release by cytochrome c oxidase in solution during the F-->O transition.
The mechanism by which electron transfer is coupled to proton pumping in cytochrome c oxidase is a major unsolved problem in molecular bioenergetics. In this work it is shown that, at least under some conditions, proton release from the enzyme occurs before proton uptake upon electron transfer to the heme/Cu active site of the enzyme. This sequence is similar to that of proton release and uptak...
متن کاملCoupled proton and electron transfer reactions in cytochrome oxidase.
Cytochrome oxidase catalyzes the four-electron reduction of O2 to water and conserves the substantial free energy of the reaction in the form of a protonmotive force. For each electron, two full charges are translocated across the membrane, resulting in a voltage. One of the mechanisms to generate the charge separation in cytochrome oxidase is via a proton pump. A single reaction cycle can be m...
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عنوان ژورنال:
- Trends in biochemical sciences
دوره 13 5 شماره
صفحات -
تاریخ انتشار 1988