FERRIC AND MANGANIC SUPEROXIDE DISMUTASES IN EUGLENA-GRACILIS

Iron-containing superoxide dismutase was found in the soluble fraction from Euglena gracilis and Mn-superoxide dismutase was found in the thylakoid-bound form. Two major Fe-superoxide dismutases were isolated from the soluble fraction in the homogeneous state. Their absorption spectra, molecular weights, subunit structures, and metal contents resemble those of the Fe-enzymes from procaryotes. However,the Euglena enzymes are more sensitive to heating, to denaturants, and to H2O2 and less sensitive to azide than are the procaryote enzymes. The amino acid composition of the Euglena enzyme differs substantially from the compositions of the enzymes from procaryotes. © 1979.