Comparative study of fibrinogen degradation by four arginine ester hydrolases from the venom of Agkistrodon caliginosus (Kankoku-Mamushi).
When purified capillary permeability-increasing (CPI)-enzyme-1, CPI-enzyme-2, kininogenase-1 or kininogenase-2 was incubated with human fibrinogen at a ratio of 1:100 by weight, a loss of fibrinogen coagulability was seen at prolonged incubation times. CPI-enzyme-2 and kininogenase-1 caused a rapid loss of coagulability, while CPI-enzyme-1 and kininogenase-2 acted more slowly. When human fibrinogen and each enzyme were incubated at 37 degrees C, CPI-enzyme-2 first cleaved the A alpha-chain then the B beta-chain. The action of CPI-enzyme-1 was similar, but slower. Kininogenase-1 initially caused slow degradation of the B beta-chain than the A alpha-chain, while kininogenase-2 only caused slow cleavage of the A alpha-chain. Although these enzymes did not show thrombin-like activity, CPI-enzyme-2 was able to release fibrinopeptide B faster than fibrinopeptide A, while kininogenase-1 only released fibrinopeptide A. These results indicate that these enzymes differ in their ability to degrade human fibrinogen.