Heterogeneity of copper-induced superoxide dismutase in rat liver lysosomes.
Preparations of liver large granule fraction from control and copper-injected rats were treated with digitonin (0.01-0.16 mg/mg protein) and supernatants rich in lysosomal matrix and in mitochondrial intermembrane space were obtained. After copper injection the superoxide dismutase activity in all supernatants was significantly increased. The granular CuZn-superoxide dismutase in the two animal groups was localized in lysosomes only. The cytosolic and lysosomal CuZn-superoxide dismutase in control preparations showed an equal electrophoretic pattern (two peaks with Rf = 0.42 and 0.47). After copper injection three new electrophoretic peaks of the lysosomal CuZn-superoxide dismutase activity (with Rf = 0.37, 0.52 and 0.62 respectively) appeared. The increased heterogeneity of the granular CuZn-superoxide dismutase activity after copper injection is explained by the oxidative degradation of the CuZn-superoxide dismutase in lysosomes.
D000818:Animals; D003300:Copper / Q000494:pharmacology*; D004589:Electrophoresis, Disc; D004790:Enzyme Induction / Q000187:drug effects; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008247:Lysosomes / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013482:Superoxide Dismutase / Q000096:biosynthesis*
D003300:Copper; D013482:Superoxide Dismutase