Viper venom toxins

Viper venom toxins represent a complex mixture of bioactive proteins and peptides that serve as the primary pathological agents in snakebite envenomation by the Viperidae family [2, 3]. These toxins include major enzyme families such as phospholipases A2 (PLA2s), snake venom metalloproteinases (SVMPs), and serine proteases, which collectively induce hemotoxicity, tissue necrosis, and coagulopathy in victims [1, 2]. While these toxins share significant structural homology across related species, geographic and evolutionary pressures lead to substantial variation in their functional epitopes and enzymatic potency [1]. In a therapeutic context, these toxins are the primary targets for antivenoms, which consist of purified antibodies or antibody fragments designed to neutralize venom activity [3]. Recent drug development has also focused on broad-spectrum small molecule inhibitors, such as varespladib for PLA2s and marimastat for SVMPs, to provide more stable and geographically versatile treatments for snakebite [4]. Understanding the diversity and homology of these toxins is critical for addressing the global challenge of antivenom efficacy and the high morbidity associated with ophitoxicoses [2, 3].

Other names

Homologous venom toxins from related viper species and geographic variantsViperid toxinsSnake venom proteinsViper venom antigens

Antivenoms utilize polyclonal antibodies to bind and neutralize the toxic enzymatic and non-enzymatic sites of venom proteins, preventing their interaction with host physiological targets [1, 2]. Small molecule inhibitors like varespladib act as competitive inhibitors of specific toxin families, such as phospholipase A2, by binding to the active site and blocking catalytic activity [4].