Processive interfacial catalysis by mammalian 85-kilodalton phospholipase A2 enzymes on product-containing vesicles: application to the determination of substrate preferences

Substrate specificities of the human and rat kidney 85-kDa phospholipase A2 enzymes (hmv PLA2) were identified in a setting where hydrolysis of substrate vesicles happens without desorption of enzymes from the interface. The rat kidney enzyme binds to vesicles which consist of hydrolysis reaction products of substrate 1-stearoyl-2-arachidonyl-sn-gylcero-3-phosphocholine (SAPC), 10 mol % arachidomic acid (20:4) and 1-stearoyl-sn-glycero-3-phosphocholine (S-lyso-PC).