pH Dependency of Kinetic Parameters and Reaction Mechanism of Beef Liver Catalase
- 1 February 1979
- journal article
- research article
- Published by Oxford University Press (OUP) in The Journal of Biochemistry
- Vol. 85 (2) , 473-479
- https://doi.org/10.1093/oxfordjournals.jbchem.a132353
Abstract
The pH-dependence of the kinetic parameters in H202 decomposition by beef liver catalase was investigated. At pH 7·0, the ternary complex (ESS) decomposition rate was about 100 times faster than ESS formation (42 μM H2O2 and the value of the Michaelis constant was 0·025 M. From ethanol competition experiments, two different proton dissociation constants of the enzyme (pKe1= pKes2=5·9 were obtained for the binding of first and second H2O2 molecules. Another pKa value (pKes1 of 4·2 was obtained from the pH dependence of overall rate constant (k0 The reaction mechanism of catalase was discussed in relation to these ionizable groups.This publication has 4 references indexed in Scilit:
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