Effect of some free radicals on superoxide dismutase and carboxypeptidase - A review

Abstract

Free radicals are species with unpaired electron in their outermost shell. Most free radicals come from oxygen or nitrogen atoms. Radical species such as superoxide radical, hydroxyl radicals and hydrated electron are called the primary radicals of water radiolysis and can be produced by irradiating water molecule. Inorganic radicals on the other hand are formed by irradiating aqueous solution of enzyme containing sodium or potassium salt of the radical to be produced. Superoxide dismutase, an important antioxidant enzyme can be inactivated by hydrogen peroxide at His-118 of the active site of the enzyme, while hydrated electron was found to be completely ineffective as inactivating specie. Hydrated electron was also found to be completely ineffective in the inactivation of carboxypeptidase, while there appears to be some relative efficiency with hydrogen atom.

Keywords: hydroxyl radical (^.OH); hydrogen atom (H^.); hydrated electron (e^-_aq); superoxide dismutase SOD; Superoxide radical (O2^.-)