PHOSPHOLIPASE-A-2 CONTAMINATION OF COBRA VENOM FACTOR PREPARATIONS - BIOLOGIC ROLE IN COMPLEMENT-DEPENDENT INVIVO REACTIONS AND INACTIVATION WITH PARA-BROMOPHENACYL BROMIDE

  • 1 January 1978
    • journal article
    • research article
    • Vol. 91  (3) , 517-+
Abstract
Cobra venom factor (CoF), the anticomplementary protein in Naja naja cobra venom, is usually purified by sequential ion exchange and gel filtration chromatography. CoF prepared in this manner contains small but significant quantities of phospholipase A2 activity. This acyl hydrolase activity can be simply and efficiently removed on a large scale by treatment of CoF with p-bromophenacyl bromide (BPB), an irreversible modifier of the histidine residue in the active site of phospholipase A2. BPB treatment does not alter the anticomplementary activity of CoF. In vivo experiments utilizing intratracheal injections of control and BPB-treated CoF, as well as pure phospholipase A2, revealed that contaminating phospholipase A2, and not the anticomplementary protein, was responsible for the observed acute neutrophil-associated lung injury [in rabbits]. Phospholipase A2 had no effect on the hypotensive and thrombocytopenic effects of CoF injected i.v. into rabbits. Depletion of circulating C3[complement component 3]-C9 by i.p. injections of CoF was not altered by removal of phospholipase A2 activity with BPB.