The isolation and partial characterization of chymotrypsinogen from the pancreas of the ostrich ( Struthio camelus)

Abstract

1. 1. Cationic chymotrypsinogen from the pancreas of the ostrich was purified to homogeneity by sulfuric acid extraction of pancrei, (NH 4) 2SO 4 fractionation and SP-Sephadex C-50 and Sephadex G-100 chromatography. 2. 2. The final preparation was homogeneous when subjected to SDS-PAGE, isoelectric focusing and sedimentation equilibrium centrifugation. The M min value obtained from amino acid analysis was 25,572 Da. A mean sedimentation coefficient of 2.575 S was obtained by sedimentation velocity centrifugation. 3. 3. N-tenninal analysis by dansylation showed an Ala residue which is the N-terminal of a neo-chymotrypsinogen. 4. 4. The effects of pH, temperature and inhibitors (LBTI, PMSF, TPCK and DFP) on the chymotryptic activity were examined. A K m -value for ATEE as substrate was found to be 0.57 mM.