Purification and Characterization of Iron-Containing Superoxide Dismutase from Anabaena Variabilis Kutz ex Born. et Flah
V. Padmapriya* and N. AnandCentre for Advanced Studies in Botany, University of Madras, Guindy Campus, Chennai - 600 025 (India).
Abstract: Cytosolic iron-containing superoxide dismutase (FeSOD; EC: 1.15.1.1) was purified to homogeneity from the cyanobacterium, Anabaena variabilis Kutz. The stepwise purification consisted of ammonium sulphate precipitation, anion-exchange chromatography and gel-filtration column chromatography. The purified enzyme was hydrogen peroxide-sensitive, confirming the enzyme to be of the iron type. Purification of 269 folds was achieved and specific activity of 700 U/mg protein obtained. Homogeneity of the purified enzyme by denaturing electrophoretic analysis showed the presence of a single band in the range of 41.4 KDa. Metal analysis of the purified enzyme showed the presence of 0.88 g atoms of iron in 41400 g of the purified enzyme. The purified SOD enzyme from A. variabilis had pH optimum of 7.4 and was active even after 1 h incubation at pH 7-7.4. The enzyme was heat-labile and was susceptible to dimethyl sulfoxide (DMSO) treatments above 20%. The UV-visible spectrum of the purified enzyme at room temperature had peaks at 253 nm and 267 nm.
Keywords: Purification; characterization; iron superoxide dismutase; cyanobacteria; Anabaena variabilis Back to TOC