Forward operation of adenine nucleotide translocase during F0F1-ATPase reversal: critical role of matrix substrate-level phosphorylation.

ABSTRACT: In pathological conditions, F(0)F(1)-ATPase hydrolyzes ATP in an attempt to maintain mitochondrial membrane potential. Using thermodynamic assumptions and computer modeling, we established that mitochondrial membrane potential can be more negative than the reversal potential of the adenine nucleotide translocase (ANT) but more positive than that of the F(0)F(1)-ATPase. Experiments on isolated mitochondria demonstrated that, when the electron transport chain is compromised, the F(0)F(1)-ATPase reverses, and the membrane potential is maintained as long as matrix substrate-level phosphorylation is functional, without a concomitant reversal of the ANT. Consistently, no cytosolic ATP consumption was observed using plasmalemmal K(ATP) channels as cytosolic ATP biosensors in cultured neurons, in

SUBMITTER: Chinopoulos C 

PROVIDER: S-EPMC2887268 | biostudies-literature | 2010 Jul

REPOSITORIES: biostudies-literature