The formation of ES of cytochrome-c peroxidase: a comparison with lactoperoxidase and horseradish peroxidase.
The activation energy for the formation of the first red compound, ES, for cytochrome-c peroxidase (ferrocytochrome-c: hydrogen-peroxide oxidoreductase, EC 1.11.1.5) by i-propyl hydroperoxide and the rate constants for the formation of ES with various hydroperoxides have been determined. Multivariate data analysis by the partial least-squares model in latent variables has been used to compare the rate constants with the corresponding rate constants for the formation of compound I from lactoperoxidase and two isoenzymes of horseradish peroxidase. The results show that the rate of formation of ES from cytochrome-c peroxidase is highly correlated with the pKa of the hydroperoxides. The activation energy for the formation of ES with i-propyl hydroperoxide is close to the corresponding value for hydrogen peroxide.
D003578:Cytochrome-c Peroxidase / Q000378:metabolism*; D006735:Horseradish Peroxidase / Q000378:metabolism*; D007700:Kinetics; D007784:Lactoperoxidase / Q000378:metabolism*; D010544:Peroxidases / Q000378:metabolism*; D011485:Protein Binding; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D013379:Substrate Specificity
D006735:Horseradish Peroxidase; D007784:Lactoperoxidase; D010544:Peroxidases; D003578:Cytochrome-c Peroxidase