Mode of Action of Membrane Perturbing Agents: Snake Venom Cardiotoxins and Phospholipases A
Abstract
Cardiotoxins (CTXs) and melittin are potent membrane perturbing agents that interact in mutual synergism with phospholipase A2 (PLA2). The present studies support the hypothesis that there is a hemolytic component of at least one of the CTXs not dependent on PLA2 activity, but that is enhanced by PLA2 contamination. Melittin and CTX elevate levels of diglycerides in airway epithelial cells (melittin) and skeletal muscle (melittin, CTX). The effects of CTX on normal muscle cannot be attributed to activation of tissue phospholipase A2 activity, as suggested by other investigators. The present study demonstrates that melittin does not at all enhance the action of bee venom PLA2 activity on mixed micelles in the presence of NaCl. Melittin and CTX act by similar, but not identical mechanisms, based on similarities and differences in their interactions with PLA2 and differences in effects on lipid metabolism in cell cultures. Certainly bee venom and snake venom PLA2s differ markedly in their interactions with CTXs and melittin. Keywords: Membrane active compounds, Phospholipase A, Snake venom cardiotoxins, Toxins.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 15, 1990
- Accession Number
- ADA225324
Entities
People
- Jeffrey E. Fletcher