Abstract: A new capillary zone electrophoresis method (CZE) has been established for the interaction analysis of protein C (PC) with a protein C activator (PCA) from Agkistrodon acutus venom. The analysis was performed on an uncoated fused-silica capillary with 75 μm i.d. and a total length of 60.2 cm (50 cm to the detector) with a buffer solution of 50 mmol/L Tris-HCl (pH 7.4) and 198 nm of wavelength. The factors which influence the separation of the PCA, such as buffer solution and ion concentration, and the interaction between the PCA and PC incubated for different times at 37.5 ℃ were studied. The linear range was from 10 to 300 mg/L. The limit of detection was 3 mg/L (S/N=3). The relative standard deviation (RSD) for the migration time of the PCA was 0.56%. The RSD for the peak area was 3.8% (n=6). The equal volumes of the PCA (200 mg/L) and PC (60 mg/L) were incubated for five minutes, at which their binding rate reached the maximum. And no hydrolyzed peptide chain from PC was found in the electropherogram. The PCA from Agkistrodon acutus venom could activate PC directly through changing the space conformation of PC. The method is simple, and highly sensitive with high resolution, and will provide important theoretical basis for the rapid detection of venom proteins and their activities in the future.

Key words: Agkistrodon acutus venom, interaction, protein C (PC), protein C activator (PCA), capillary zone electrophoresis (CZE)