Denaturation of Copper Zinc Superoxide Dismutase by Guaniding Hydrochloride

The electron-transfer reaction between Fe(CN)(6)(4-) and copper zinc superoxide dismutase was used to detect the conformational changes of the active site of the enzyme. The analysis of the absorption, CD, ESR and fluorescence spectrum has provided the information of the conformational changes of the enzyme molecule at different sites. It was shown that inactivation occurred before the conformational change of the enzyme molecule. The results of kinetic analysis showed that conformational changes of the active site correlated closely with the changes of enzyme activity. Although being a relative stable metalloenzyme, copper zinc superoxide dismutase has a relative flexible active site.