Atroxase (EC 3.4.24.43) is an enzyme. This enzyme catalyses the following chemical reaction Cleavage of His5-Leu, Ser9-His, His10-Leu, Ala14-Leu and Tyr16-Leu of insulin B chain This endopeptidase is present in the venom of the western diamondback rattlesnake (Crotalus atrox).