Mode of Action of Membrane Perturbing Agents: Snake Venom Cardiotoxins and Phospholipases A
Abstract
CTXs have at least two mechanisms of action. The first has a rapid onset and is reversible. The second has a prolonged latency to onset and results in cell death (cytolytic action). Free fatty acids in the membrane markedly affect CTX action. Melittin differences in their interactions with PLA2 and differences in effects on lipid metabolism in cell cultures. Bee venom and snake venom PLA2s differ markedly in their interactions with CTXs and melittin. The most consistent interaction (marked mutual synergism) between the membrane perturbing toxins (CTX and melittin) and any PLA2 is allowing the PLA2 enzyme to penetrate to formerly unavailable substrates. The Naja naja kaouthia CTX and melittin do possess activities not dependent on venom PLA2 contamination in the toxin fraction. These toxins both elevate free fatty acids and diglycerides by a mechanism unrelated to activation of endogenous PLA2 activity. Keyword: Membrane active compounds, Phospholipase A, Snake venom cardiotoxins, Toxins.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 30, 1990
- Accession Number
- ADA228666
Entities
People
- Jeffrey E. Fletcher