Direct measurement of proton release by cytochrome c oxidase in solution during the F -> O transition

by Zaslavsky, D.; Sadoski, R. C.; Rajagukguk, S.; Geren, L.; Millett, F.; Durham, B.; Gennis, R. B.

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 uptake observed for the light-activated proton pump bacteriorhodopsin. In the case of cytochrome c oxidase, this observation means that both the ejected proton and the proton required for the chemistry at the enzyme active site must come from an internal proton pool.

Journal
Proceedings of the National Academy of Sciences of the United States of America
Volume
101
Issue
29
Year
2004
Start Page
10544-10547
URL
https://dx.doi.org/10.1073/pnas.0401521101
ISBN/ISSN
1091-6490; 0027-8424
DOI
10.1073/pnas.0401521101