Snake venom zinc metalloproteinase that inhibits platelet aggregation by cleaving platelet glycoprotein Ib alpha (GP1BA) at Glu-298/Asp-299, and abolishes binding of von Willebrand factor (VWF) to GPIBA. Binds 1 zinc ion per subunit. Monomer. Expressed by the venom gland. Belongs to the venom metalloproteinase (M12B) family. P-III subfamily. P-IIIa sub-subfamily.