Abstract
1. The heat denaturation of BPN' and DFP- inhibited BPN' did not follow a simple first-order reaction but was a more complex reaction.
2. A study of the effect of the ionic strength of sodium chloride solution on the reaction shows that the ionic process during the heat denaturation of BPN' and DFP-inhibited BPN' in sodium chloride solution is an ion-ion reaction of ions with opposite signs.
3. A study of the effect of the ionic strength of phosphate solution on the reaction shows that the phosphate anion has two effect on the heat denaturation of BPN' and DFP-inhibited BPN'. One is a specific reaction of phosphate anion and the other is the ordinary reaction of ionic solutions.
4. During the heat denaturation of BPN' and DFP-inhibited BPN', the difference in the heat of activation is small, and the dif-ference in the entropy of activation is quite large.
The author wishes to express his sincere thanks to Prof. K. Okunuki for his continuous encourage-ment and interest during the course of this work and also to Nagase Co. for kind supplying crystalline bacterial proteinase, “Nagarse”.
