| Abstract: | Abstract— Trypsin inactivated by u.v. radiation, gamma radiation, visible radiation in the presence of sensitizing dyes, and autolysis, was examined by the method of disc electrophoresis. Untreated Worthington twice crystallized salt-free trypsin separated into four bands which moved toward the cathode; the main band, which had the greatest mobility, contained all of the detectable tryptic activity. The next most mobile band has been assumed to be a chymotrypsin contaminant. The other two bands are of unknown nature. A progressive loss of all the bands was observed when the enzyme was inactivated by those procedures which produce a ‘damaged’ class of trypsin molecules, i.e. flavin-sensitized photooxidation, autolysis, and treatment with u.v. and gamma radiation. No loss of the main band was observed during photoinactivation with methylene blue and eosin Y as sensitizers. In this latter case, it is postulated that the trypsin inactivation products must be of such a nature that the net charge and conformation of the protein is not greatly changed, thus permitting all of the protein to remain in the same band during electrophoresis. |
