Russell's viper venom factor X activator (RVV-X)

Russell's viper venom factor X activator (RVV-X) is a major, highly toxic zinc-dependent metalloproteinase found in the venom of Russell's viper (*Daboia russelii*). It belongs to the P-IIId class of snake venom metalloproteinases and is responsible for activating blood coagulation factor X by specific proteolytic cleavage, thereby initiating rapid clot formation, disseminated intravascular coagulation, and widespread tissue damage. The toxin contributes to multiple systemic pathologies following envenomation, making it a major drug and diagnostic target for antivenom development and laboratory detection of clotting disorders. Other minor toxins (such as various phospholipase A2 isoforms) exist in the venom, but RVV-X is the canonical therapeutic target.

Other names

RVV-XFactor X activating enzyme from Russell's viper venomRussell's viper factor X activatorSnake venom metalloproteinase (SVMP)P-IIId SVMP

RVV-X acts through enzymatic cleavage and activation of factor X at Arg194-Ile195. This is a Zn^2+-dependent hydrolysis reaction that initiates the coagulation cascade via direct factor X activation.