Characterization of kallikrein-like enzyme from Crotalus ruber ruber (red rattlesnake) venom

Abstract

1. 1. A kallikrein-like enzyme from the venom of Crotalus ruber ruber (red rattlesnake) had been isolated and characterized by Mori and Sugihara. The enzyme was active upon the kallikrein substrates, Pro-Phe-Arg-MCA and z-Phe-Arg-MCA, and slightly hydrolyzed Boc-Val-Leu-Lys-MCA, and Boc-Phe- Ser-Arg-MCA. 2. 2. Unlike thrombin, the newly isolated kallikrein-like enzyme did not cause formation of a fibrin clot when fibrinogen was mixed with the enzyme. 3. 3. The Bβ chain of fibrinogen was first split and Aα chain was cleaved later. Pancreatic kallikrein hydrolyzed only the Aα chain without affecting the Bβ chain. 4. 4. The kallikrein-like enzyme produced kallidin (Lys-bradykinin) by splitting the Met-Lys bond instead of producing bradykinin. 5. 5. The kallikrein analog JSI-450 (Ac-Phe-Ser-Pro-Phe-Arg-Ser-Val-Gln-Val-Ser-NH 2) was also cleaved at the site of the Arg-Ser bond. 6. 6. Its NH 2-terminal amino acid sequence (Val-Ile-Gly-Gly-Asp-Glu-Cys-Asn-Ile-Asn-Glu-Arg-Pro-Phe- Leu-Val-Ala-Leu-Tyr-Asp-Ser-) is homologous to the rat pancreatic kallikrein and other snake venom proteases.