1956 年 43 巻 4 号 p. 495-508
By assaying the activity and determining the denaturation by the proteolytic method at the same time, the relation between inactivation and denaturation of crystalline beef catalase was investigated in the duration of treatment with urea, perturbators, and four specific inhibitors. The “ratio of inactivation” (RI) and the “ratio of denaturation” (RD) of the catalase almost coincided with one another at any stage in the du-ration of urea-treatment, but the “RD” was slightly larger than the “RI” because catalase even native, was slightly digested by the proteinase. So called “perturbators, ” such as benzoate and salicylate, behaved similarly to urea. Cyanide and fluoride inhibited the enzyme activity without denaturation of the enzyme protein and the inactivated enzyme was completely reactivated by the dilution. Azide and hydroxyl-amine also inactivated the enzyme without denaturation, but the inactivated enzyme was not reactivated by the dilution. As the time course of denaturation of catalase in the presence of urea was not changed by the addition of azide, it was concluded that the above specific in-hibitors have not affect at all on the secondary intramolecular structure of protein moiety of catalase molecule.
