An assessment of the role of proton leaks in the mechanistic stoichiometry of oxidative phosphorylation.
Rat liver mitochondria were incubated in the presence of varying concentrations of ATP, followed by ADP to initiate phosphorylation. Analysis of phosphorylation to oxygen ratios (P/O) was carried out with varied initial phosphorylation potentials (or ATP/ADP ratios). Rates of phosphorylation and respiration and magnitude of membrane potential (delta psi) were measured. The results are discussed in the framework of P/total O and P/"extra" O ratios in determination of the mechanistic P/O ratio. It is concluded that the former underestimates, and the latter overestimates the mechanistic P/O ratio.
Davis
E J
EJ
Indiana University School of Medicine, Department of Biochemistry and Molecular Biology, Indianapolis 46202-5122.
Davis-van Thienen
W I
WI
D000244:Adenosine Diphosphate / Q000378:metabolism / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D008564:Membrane Potentials; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism*; D010085:Oxidative Phosphorylation; D010101:Oxygen Consumption; D010766:Phosphorylation; D011522:Protons; D051381:Rats
D011522:Protons; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate