Phospholipase A2 pseudexin (Pseudexin)

Phospholipase A2 (PLA2) myotoxins from the venom of the Red-bellied black snake (Pseudechis porphyriacus), primarily known as pseudexins, are potent enzymes that catalyze the hydrolysis of the sn-2 ester bond of glycerophospholipids (UniProt: P00611). These toxins are major components of the venom and are responsible for significant local and systemic myotoxicity, leading to muscle fiber necrosis and rhabdomyolysis (PubMed: 15530651). In addition to their enzymatic activity, they exhibit non-enzymatic pharmacological effects, including anticoagulant activity and potential presynaptic neurotoxicity (PubMed: 8638250). Clinically, envenomation results in elevated creatine kinase levels and potential secondary renal failure due to myoglobinuria (Toxinology.com). Therapeutic intervention focuses on the use of specific or cross-reactive antivenoms to neutralize the toxin's activity, while small-molecule inhibitors like varespladib are being investigated as potential treatments to inhibit the enzymatic site of these PLA2s (PubMed: 27153755). Understanding these toxins is critical for developing more effective treatments for elapid snakebites in Australia.

Other names

Pseudexin APseudexin BPseudexin CPseudechis porphyriacus venom PLA2Red-bellied black snake myotoxin

Neutralization of the toxin's enzymatic and membrane-binding sites by specific antibodies or competitive inhibition of the catalytic site by small molecules like varespladib (PubMed: 27153755).