A proposal for the site and mechanism of redox-linked proton translocation in cytochrome c oxidase.
In this paper, we present a detailed mechanistic model for the redox-linked proton pump of cytochrome c oxidase. Using the spectroscopic properties of CuA, we have constructed a molecular orbital model for the electronic structure of the CuA site. One prediction of this model is that a ligand rearrangement should occur upon reduction of CuA. We further describe a detailed mechanism for proton pumping which utilizes this redox-linked CuA ligand rearrangement as its central feature. The turnover cycle of this proton pump model is then discussed in terms of the theoretical thermodynamic and kinetic requirements of a redox-linked proton pump.
Chan
S I
SI
Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena 91125.
Li
P M
PM
Nilsson
T
T
Gelles
J
J
Blair
D F
DF
Martin
C T
CT
D001665:Binding Sites; D003300:Copper / Q000378:metabolism; D004579:Electron Transport; D003576:Electron Transport Complex IV / Q000378:metabolism*; D007700:Kinetics; D008024:Ligands; D008958:Models, Molecular; D010084:Oxidation-Reduction; D011487:Protein Conformation; D011522:Protons; D013816:Thermodynamics
D008024:Ligands; D011522:Protons; D003300:Copper; D003576:Electron Transport Complex IV