Studies on phospholipid structures in mitochondria of animals injected with cobra venom or phospholipase A

Abstract

Heated cobra venom did not uncouple oxidative phosphorylation in submitochondrial fragments prepared by digitonin extraction. These experiments suggest that venom does not directly inhibit the phosphorylating enzymes. Addition of small quantities of crystalline phospholipase A enhanced spontaneous swelling of fresh mitochondria. The effect could be reversed by lecithin. Mitochondria of animals injected with phospholipase also showed greater swelling than the controls. Evidence presented demonstrates that the various effects produced by cobra venom on mitochondrial metabolism result from hydrolysis of mitochondrial phospholipids by the phospholipase. The quantity of lysolecithin produced could not account for the various effects of cobra venom on mitochondrial metabolism.