Papain has been found to activate bovine chymotrypsinogen A. The optimal conditions for the activation are pH 5.0, temperature 23 °C, and enzyme/substrate ratio 1:20. The chymotrypsin obtained by the papain activation has been isolated. A significant difference between this enzyme and α-chymotrypsin is the absence of the three amino acids (Ser, Gly, and Leu) occupying the C-terminal of the A-chain of the former.