SOD and catalase inactivation by singlet oxygen and peroxyl radicals

摘要: Both superoxide dismutase and catalase are readily deactivated by singlet oxygen the radicals produced in pyrolysis of 2,2′-azo-bis-(2-amidinpropano) under aerobic conditions. The rate constant for loss enzymatic activity induced 3.9 × 107 2.5 M−1 sec−1 SOD catalase, respectively. similarity between these values implies that systems where exposed to similar concentrations, it can be expected a parallel inactivation both enzymes. enzymes 2,2′-azo-bis-(2-amidinopropane) conditions follows first-order kinetics at low enzyme concentrations zero-order higher concentrations. Although is similar, this results from compensation effects because there wide differences reactivity towards peroxyalkyl radicals. Catalase considerably more reactive, but large number protein/radical reactive interactions needed inactivate one enzyme. On other hand, smaller, average decreases nearly 20% each SOD/radical interaction.