Mitochondrial ATPase of Zajdela hepatoma. VI. Effect of extramitochondrial ATP and pH on uncoupler-sensitivity of mitochondrial ATPase activity.

Coupled Zajdela hepatoma mitochondria were reported to exhibit uncoupler-insensitive ATPase activity. The results of this study show that under specific conditions the ATPase activity of Zajdela hepatoma mitochondria can be stimulated by uncouplers. These conditions include (a) the addition of ATP to the mitochondria before the uncoupler in the ATPase activity assay or (b) elevation of pH (above 8.5) of the ATPase activity assay medium.