Copper, zinc-superoxide dismutase (Cu, Zn-SOD) was purified from rat liver using Tsuchihashi fractionation, acetone treatment, ion exchange chromatography (DE-52, CM-52) . The purified enzyme showed 2bands in polyacrylamide gel electrophoresis (PAGE), but in SDS-PAGE and isoelectric focusing showed a single band (M.W. 16, 000, pH 5.1) . It was found that Cu, Zn-SOD had electrophoretic variants and there was no immunological difference among the variants.Immunolocalization in various organs of rat was investigated using antiserum against Cu, Zn-SOD. Localization in rat organs was almost the same as that in human, previously reported.Cu, Zn-SOD was seen in the cells which function was related to the transport of electrocyte and water in the cases of parietal cells, duct epithelium of salivary gland and pancreas, intrahepatic biliary duct, epithelium of intestine, distal convoluted tubles and Henle's loops.Futhermore, localization of the islets of Langerhans and the medulla in adrenal gland may show that superoxide radical plays a role in the function of the endocrine cells.On the other hand, localization in the SOD positive cells was found in the cytoplasm and partially in the nucleus. SOD in the nucleus may protect the nucleic acid from the damage by superoxide radical.In conclusion, superoxide radical and SOD plays an important role in various organs.
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