Some properties of a capillary permeability-increasing enzyme-2 from the venom of Agkistrodon caliginosus (Kankoku-Mamushi).

Capillary permeability-increasing enzyme-2 (CPI-enzyme-2) consists of a single polypeptide chain with an isoelectric point of pH 3.5. The enzyme is composed of 369 amino acid residues, based on a mol. wt of 44,000, and contains 20.3% carbohydrate. Both arginine ester hydrolytic and capillary permeability-increasing activities of the enzyme were inhibited by treatment with diisopropylfluorophosphate, indicating that the enzyme is a serine proteinase. The N-terminal amino acid sequence shows homology with that of CPI-enzyme-1 and similarity to those of batroxobin or kallikrein-like enzyme from other snake venoms.