Daboia siamensis factor V activator (DsVVA)

Daboia siamensis factor V activator is a potent procoagulant serine protease found in the venom of the Eastern Russell's Viper. Unlike many other snake venom procoagulants that are metalloproteinases, this specific toxin is a highly specific serine protease that activates host Factor V by cleaving the heavy chain-light chain junction, mimicking the action of thrombin but without the regulatory feedback mechanisms. This activation leads to the rapid formation of the prothrombinase complex, resulting in massive thrombin generation and subsequent consumptive coagulopathy in snakebite victims. In a clinical context, this molecule is the primary target for therapeutic antivenoms, which aim to neutralize its enzymatic activity to prevent life-threatening systemic bleeding and disseminated intravascular coagulation. Beyond its role in pathology, the toxin is utilized in diagnostic laboratory medicine to assay Factor V levels in human plasma.

Other names

Russell's viper venom factor V activatorRVV-VDaboia siamensis serine protease 1Factor V-activating enzymeVipera russelli factor V activator

Antivenoms work by polyclonal antibody-mediated neutralization of the toxin's enzymatic activity and facilitating its clearance from the systemic circulation.