Biological aging does not lead to the accumulation of oxidized Cu,Zn-superoxide dismutase in the liver of F344 rats.
Cu,Zn-Superoxide dismutase (SOD) was isolated from the liver of 3-, 12-, and 26-month-old Fisher 344 (F344) rats. Specific activity and metal content of the enzyme, purified by ion-exchange and size-exclusion chromatography, did not significantly change with age. Electrospray ionization-mass spectrometry and amino acid analysis of Cu,Zn-SOD apoprotein, further purified by reverse-phase HPLC, showed neither significant loss of amino acids nor accumulation of oxidized isoforms with age. When bovine Cu,Zn-SOD, oxidized with H(2)O(2) in vitro, was added to rat liver homogenate, we reisolated circa 70% of the oxidized bovine Cu,Zn-SOD together with the rat isoform, showing that oxidized Cu,Zn-SOD can be recovered from tissue homogenate. Therefore, our data do not confirm an earlier hypothesis that oxidatively modified Cu,Zn-SOD protein accumulates in the liver of aged F344 rats.
Ghezzo-Schöneich
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Department of Pharmaceutical Chemistry, University of Kansas, Lawrence 66047, USA.
Esch
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Sharov
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Schöneich
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D000375:Aging / Q000502:physiology*; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D003300:Copper / Q000032:analysis; D008099:Liver / Q000201:enzymology* / Q000378:metabolism; D008297:Male; D016877:Oxidants / Q000378:metabolism; D010084:Oxidation-Reduction; D051381:Rats; D011916:Rats, Inbred F344; D021241:Spectrometry, Mass, Electrospray Ionization; D013482:Superoxide Dismutase / Q000737:chemistry / Q000378:metabolism*; D015032:Zinc / Q000032:analysis
D000596:Amino Acids; D016877:Oxidants; D003300:Copper; D013482:Superoxide Dismutase; D015032:Zinc