Comparison of the Action of Chymotrypsin Alpha and Chymotrypsin B upon Several Protein Substrates

Laskowski isolated in 1947 from beef pancreas a crystalline zymogen of a proteolytic enzyme. He demonstrated that this zymogen when activated was similar but not identical to chymotrypsin alpha. The crystalline activated form of this zymogen was obtained in 1948 by Laskowski and his group. The specifity of Chymotrypsin alpha and Chymotrypsin B toward synthetic substrates was found to be identical. On the other hand, it was shown that the two proteins are entirely different in respect to their isoelectric point and solubility. Therefore, it seemed interesting to investigate the behavior of the two Chymotrypsins toward protein substrates. It was hoped that some of the protein substrates might show differences in susceptibility to ward these tow chymotrypsins. Therefore, an investigation was undertaken to compare the rate of digestion of several protein substrates by chymotrypsin alpha and hymotrypsin B. This investigation comprises the experimental work of this thesis.