Lysophospholipid breakdown in cobra venom-treated rabbit erythrocytes

Rabbit erythrocyte phospholipase B (lysolecithin acyl-hydrolase E.C. 3.1.1.5) hydrolyses the lysophospholipids produced in Ringhals cobra venom—treated rabbit erthrocytes and osmotic ghosts by the action of the venom phospholipase A (phosphatide acyl-hydrolase E.C. 3.1.1.4). Raising the incubation temperature of the osmotic hemolysate-venom mixture to 60° leads to inactivation of the erythrocyte phospholipase B with preservation of the lysocompounds formed due to the action of the heat-stable venom phospholipase A. Subjecting the rabbit erythrocytes to various hemolytic agents, such as hypotonic medium, saponin, digitonin or cobra venom-direct lytic factor (DLF), causes liberation of phospholipase B into the particle-free supernatants, as indicated by hydrolysis of added lysolecithin.