Influence of structure, pH and membrane potential on proton movement in cytochrome oxidase

• Published in: Biochimica et biophysica acta Vol. 1555; no. 1; pp. 96 - 100
• Main Authors: Mills, Denise A, Ferguson-Miller, Shelagh
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 10.09.2002
• Subjects: Biological Transport, Active; Cytochrome oxidase; Electron Transport Complex IV - chemistry; Hydrogen-Ion Concentration; Membrane Potentials; Models, Molecular; Oxidation-Reduction; Protein Conformation; Proton exit; Proton pathway; Protons; Respiratory control; Rhodobacter sphaeroides; Cytochrome oxidase; Proton pathway; Proton exit; Respiratory control
• ISSN: 0005-2728; 0006-3002; 1879-2650
• DOI: 10.1016/S0005-2728(02)00261-X

Cytochrome c oxidase (C cO) reconstituted into phospholipid vesicles and subject to a membrane potential, exhibits different characteristics than the free enzyme, with respect to effects of mutations, pH, inhibitors, and native structural differences between C cO from different species. The results indicate that the membrane potential influences the conformation of C cO and the direction of proton movement in the exit path. The importance of the protein structure above the hemes in proton exit, back leak and respiratory control is discussed.