Phospholipase A2 venom enzyme and neurotoxic complex (PLA2)

Phospholipase A2 (PLA2) enzymes are critical components of viperid venoms, including those from the Mojave rattlesnake (Crotalus scutulatus) (UniProt, 2024). These enzymes catalyze the hydrolysis of the sn-2 ester bond of phospholipids, leading to membrane disruption and the release of arachidonic acid (NCBI, 2023). In C. scutulatus, the primary PLA2 is the Mojave toxin, a potent heterodimeric presynaptic neurotoxin consisting of an acidic, non-toxic subunit and a basic, toxic PLA2 subunit (PubMed, 2022). This complex targets the presynaptic nerve terminal, inhibiting acetylcholine release and causing neuromuscular blockade and respiratory failure (StatPearls, 2024). Therapeutic intervention primarily involves antivenoms that neutralize these toxins through antibody binding, while small-molecule inhibitors like varespladib are being explored to directly inhibit the enzymatic activity (PubChem, 2024). The diversity of PLA2 isoforms across different species necessitates the use of polyvalent immunizing venoms to ensure broad therapeutic coverage (NIH, 2023).

Other names

Mojave toxinCrotoxin-like neurotoxinBeta-neurotoxinPhosphatidylcholine 2-acylhydrolaseCrotalus scutulatus venom PLA2Phospholipase A2 venom enzymes and PLA2-based neurotoxic complexes from Crotalus scutulatus and other immunizing venoms

Neutralization of toxic subunits via antibody binding (antivenom) or competitive inhibition of the PLA2 enzymatic active site (varespladib) (StatPearls, 2024; PubChem, 2024).