Vanadate inhibition of mitochondrial respiration and H+ ATPase activity in Saccharomyces cerevisiae

The effects of vandate on mitochondrial respiration and H+ ATPase activity in Saccharomyces cerevisiae were studied. A 50 inhibition of oxygen uptake in isolated mitochondria was produced by 4·4 mM?V2O5. Activity of H+ ATPase in whole mitochondria was inhibited by 50 by 5·5 ?M?V2O5, in submitochondrial particles by 55 ?M?V2O5; and in the chloroform?released H+ ATPase by 0·5 mM?V2O5. Vandate was also found to relieve growth inhibition caused by the mitochondrial H+ ATPase inhibitors NN??decyclohexylcarbodiimide and oligomycin. These results imply that vanadate could affect mitochondrial respiration by interacting with the H+ ATPase in S. cerevisiae.