Russell's viper venom phospholipase A2 (RVV-PLA2)

Russell's viper venom phospholipase A2 (RVV-PLA2) is a primary toxic component of the venom of the Russell's viper (Daboia russelii), one of the most medically significant snakes in Asia [1.1.1, 1.2.3]. These enzymes belong to the Group IIA secreted phospholipase A2 (sPLA2) family and function by catalyzing the hydrolysis of the sn-2 ester bond of membrane phospholipids, leading to the release of pro-inflammatory mediators like arachidonic acid [1.1.1, 1.4.1]. Clinically, RVV-PLA2 is responsible for a diverse array of pathologies, including systemic anticoagulation, presynaptic neurotoxicity, and extensive muscle damage known as myotoxicity [1.2.1, 1.2.2]. While traditional antivenoms are the standard of care, they often struggle to neutralize these small, rapidly diffusing toxins, which can lead to persistent tissue damage or late-onset symptoms [1.1.1, 1.3.3]. Consequently, RVV-PLA2 has become a major target for small-molecule inhibitors like varespladib, which aim to provide early, field-deployable treatment to mitigate the life-threatening effects of envenomation [1.3.1, 1.3.5]. The target's role in both local tissue destruction and systemic toxicity makes it a focal point for next-generation snakebite therapies [1.2.4].

Other names

svPLA2Snake venom phospholipase A2Phosphatidylcholine 2-acylhydrolaseRusstoxinU1-viperitoxin-Dr1aU1-viperitoxin-Dr1bBasic phospholipase A2 RVV-VD

Varespladib and its derivatives act as potent, competitive inhibitors of the sPLA2 active site, preventing the enzymatic hydrolysis of phospholipids and the subsequent release of toxic byproducts like arachidonic acid [1.3.1, 1.3.5]. Antivenoms provide polyclonal antibodies that bind to the toxin's surface, neutralizing its ability to interact with host cell membranes and preventing systemic toxicity [1.1.1, 1.2.4].