Heat and pH dependence of catalase. A comparative study.

Effects of pH and heat were examined on the activity of enzyme catalase from human sources (normal and pathological sera, tissue homogenates, purified catalases). The pH optimum, temperature optimum and T50 values of purified catalases were lower than those of normal, or pathological sera and tissue homogenates. On contrast, the activation energy showed its highest value in purified catalase. These findings might be explained by the post-translational modification of enzyme catalase. The obtained results failed to enhance the diagnostic role of serum catalase determination, nevertheless, gave the optimal values of pH and temperature for catalase assay.