A study on Na+ -coupled oxidative phosphorylation: ATP formation supported by artificially imposed delta pNa and delta pK in Vibrio alginolyticus cells.
Addition of Na+ to the K+-loaded Vibrio alginolyticus cells, creating a 250-fold Na+ gradient, is shown to induce a transient increase in the intracellular ATP concentration, which is abolished by the Na+/H+ antiporter, monensin. The delta pNa-supported ATP synthesis requires an additional driving force supplied by endogenous respiration or, alternatively, by a K+ gradient (high [K+] inside). In the former case, ATP formation is resistant to the protonophorous uncoupler. Dicyclohexylcarbodiimide and diethylstilbestrol, but not vanadate, completely inhibit Na+ pulse-induced ATP formation. The data agree with the assumption that Na+ -ATP-synthase is involved in oxidative phosphorylation in V alginolyticus. Interrelation of H+ and Na+ cycles in bacteria is discussed.
Dibrov
P A
PA
A. N. Belozersky Laboratory of Molecular Biology and Bioorganic Chemistry, Moscow State University, USSR.
Lazarova
R L
RL
Skulachev
V P
VP
Verkhovskaya
M L
ML
D000255:Adenosine Triphosphate / Q000096:biosynthesis*; D001693:Biological Transport, Active / Q000187:drug effects; D002462:Cell Membrane / Q000378:metabolism; D007473:Ion Channels; D010085:Oxidative Phosphorylation; D011188:Potassium / Q000378:metabolism; D011522:Protons; D012964:Sodium / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D014733:Vibrio / Q000187:drug effects / Q000378:metabolism*
D007473:Ion Channels; D011522:Protons; D000255:Adenosine Triphosphate; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium