Ageing of α-chymotrypsin: Cannibalistic and hydroxide ion reactions
- 1 July 1981
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 78 (7) , 4116-4117
- https://doi.org/10.1073/pnas.78.7.4116
Abstract
The loss of catalytic activity (irreversible denaturation) of α-chymotrypsin (EC 3.4.21.1) as a function of pH between 6 and 13 is described. Around neutrality the irreversible denaturation is second order with respect to enzyme. At high pH, the irreversible denaturation is first order with respect to enzyme and also with respect to hydroxide ion. The first- or second-order dependency on enzyme concentration has been shown both by the time course of denaturation and by the effect of enzyme concentration on the rate of denaturation. The first-order dependency on hydroxide ion was shown by a plot of the logarithm of the rate constant vs. pH. These enzyme inactivations are peptide bond cleavages at all pH values. From the kinetics, the irreversible denaturation can be described as a cannibalistic reaction of two enzyme molecules around neutrality or as a reaction of one enzyme molecule plus one hydroxide ion at high pH.Keywords
This publication has 1 reference indexed in Scilit:
- The Spectrophotometric Determination of the Operational Normality of an α-Chymotrypsin SolutionJournal of Biological Chemistry, 1961