C-type lectin-like venom proteins and coagulant toxins (Bothrops asper and Crotalus durissus) (Snaclecs/SVSPs)

C-type lectin-like proteins (snaclecs) and coagulant toxins from Bothrops asper and Crotalus durissus are a diverse group of venom components that disrupt the host circulatory system. Snaclecs are non-enzymatic proteins that bind to platelet receptors such as glycoprotein Ib (GPIb) or GPVI, as well as various coagulation factors, leading to either the activation or inhibition of platelet aggregation (Gutiérrez et al., 2009). Coagulant toxins, including snake venom serine proteases (SVSPs) and metalloproteinases (SVMPs), act by activating prothrombin or Factor X, or by directly cleaving fibrinogen into unstable fibrin clots, which results in venom-induced consumptive coagulopathy (VICC) (Slagboom et al., 2017). In Bothrops asper, these toxins are primarily responsible for severe local tissue damage and systemic hemorrhage, while in Crotalus durissus, they contribute to systemic hemostatic failure alongside neurotoxic effects (Sano-Martins et al., 2001). These proteins are the primary therapeutic targets for antivenoms, which use polyclonal antibodies to neutralize their toxic effects. Research is also ongoing into small-molecule inhibitors like varespladib and marimastat to provide rapid, field-deployable treatment options (Ainsworth et al., 2018).

Other names

SnaclecsSnake venom C-type lectin-like proteinsSnake venom serine proteasesSnake venom metalloproteinasesThrombin-like enzymesProcoagulant venom toxins

Antivenoms work by providing passive immunity through polyclonal antibodies that bind and neutralize the toxins active sites or receptor-binding interfaces (Gutiérrez et al., 2009). Experimental small molecules like varespladib inhibit phospholipase A2 activity, while metalloproteinase inhibitors like marimastat block the proteolytic activity responsible for tissue degradation and hemorrhage (Ainsworth et al., 2018).