Differential effect of 3-amino-1,2,4-triazole on multiple forms of rat liver catalase.

Injection of 3-amino-1,2,4-triazole into rats resulted in a rapid fall of liver catalase activity which gradually returned to the normal level, but the amount of catalase protein determined by the immunochemical method remained constant without any decrease in parallel with the enzyme activity. Inactivation occurred more rapidly with soluble catalase (or Catalase-II) than with catalase in peroxisomes (Catalase-III) . Rate of recovery in enzyme activity from maximum inactivation was also investigated for Catalase-II and -III, and its results indicated that Catalase-II is synthesized more rapidly than CatalaseIII.