ATP synthesis and hydrolysis in submitochondrial particles subjected to an acid-base transition. Effects of the ATPase inhibitor protein.
ATP hydrolysis or succinate oxidation by inhibitor-rich submitochondrial particles leads to a 3-fold increase in ATPase activity, with concomitant loss of about 30% of bound inhibitor protein. An acid-base transition causes similar, but smaller, effects (a 30% ATPase increase, and a loss of 8% of the inhibitor). Omitting the electrical component of the gradient completely abolished these effects. The inhibitor protein inhibits ADP phosphorylation induced by an acid-base transition but not by NADH oxidation. This is suggested to reflect the slow movement of the inhibitor protein and the brief period of acid-base jump phosphorylation.
D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008928:Mitochondria / Q000201:enzymology*; D011506:Proteins / Q000378:metabolism*; D006180:Proton-Translocating ATPases / Q000037:antagonists & inhibitors*; D013367:Submitochondrial Particles / Q000201:enzymology*; D014634:Valinomycin / Q000494:pharmacology; D000097795:ATPase Inhibitory Protein
D000255:Adenosine Triphosphate; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D011506:Proteins; D006180:Proton-Translocating ATPases; D014634:Valinomycin; D000097795:ATPase Inhibitory Protein