Role of phosphatidylserine and phosphatidylcholine in the dicyclohexylcarbodiimide-induced inhibition of mitochondrial ATPase.

Mixed phospholipids, purified phosphatidylcholine and phosphatidylserine restored the ATPase activity of submitochondrial particles pretreated with dicyclohexylcarbodiimide (DCCD). Pretreatment of mixed phospholipids with DCCD resulted in preparations which were able to transfer the inhibitor to submitochondrial particles. Phosphatidylcholine alone was fully effective. Phosphatidylserine, which apparently forms a stable bond with DCCD, was inactive. These findings suggest different functions of individual phospholipids in the DCCD-induced inhibition. The observation that phosphatidylserine displays unusual high activity in the restoration of ATPase activity in phospholipid-depleted submitochondrial particles indicates that it plays an important role in the activation of mitochondrial ATPase and deserves attention as costituent of the final receptor site for DCCD. © 1971.