[Theoretical analysis of redox-dependent protonation of hema a and Cu(A) in cytochrome c oxidase and CO-inhibited binuclear center].
One of the proposed mechanisms of functioning of cytochrome c oxidase (COX) postulates that heme a is the element pumping protons across the membrane. It is generally believed that, to support this mechanism, a substantial proton uptake/release should exist upon heme a reduction/oxidation. Two direct measurements of proton uptake/release in oxidation/reduction of heme a in CO-bound mixed-valence COX were recently reported. In this paper, we develop a general formalism for the interpretation of such experiments and discuss the results of these experiments. A control experiment is proposed to verify the conclusions made in previous studies.
Georgievskiĭ
Iu I
IuI
Department of Chemistry, University of California, Davis, CA 95616, USA.
Medvedev
E S
ES
Stuchebriukhov
A A
AA
D002248:Carbon Monoxide / Q000378:metabolism*; D003300:Copper / Q000378:metabolism*; D003576:Electron Transport Complex IV / Q000378:metabolism*; D006418:Heme / Q000031:analogs & derivatives* / Q000378:metabolism*; D010084:Oxidation-Reduction; D011522:Protons
D011522:Protons; C027728:heme a; D006418:Heme; D003300:Copper; D002248:Carbon Monoxide; D003576:Electron Transport Complex IV