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 m M ‐V 2 O 5 . Activity of H + ATPase in whole mitochondria was inhibited by 50% by 5·5 μ M ‐V 2 O 5 , in submitochondrial particles by 55 μ M ‐V 2 O 5 ; and in the chloroform‐released H + ATPase by 0·5 m M ‐V 2 O 5 . 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 .