Porcine superoxide dismutase. Isolation and characterization of a relatively basic cuprozinc enzyme.
A cuprozinc superoxide dismutase has been isolated from pig liver. The enzyme is similar to previously described cuprozinc superoxide dismutases in that it is a dimer of about 32 000 molecular weight consisting of approximately two equally sized subunits, and 2 atoms of copper and two atoms of zinc per molecule. It differs, however, from previously described cuprozinc superoxide dismutases because of its higher isoelectric point; pI 6.8 vs 4.9 for bovine enzyme. The diffusion coefficient for the porcine enzyme was determined to be 7.53 x 10(-7) cm2 s-1, while the equivalent spherical hydrodynamic radius was computed as 28.5 A. The enzyme was observed to undergo self-association with time. Sulfhydryl interaction is postulated to be involved.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002417:Cattle; D003300:Copper / Q000032:analysis; D007526:Isoelectric Point; D008027:Light; D008099:Liver / Q000201:enzymology*; D046911:Macromolecular Substances; D008970:Molecular Weight; D012542:Scattering, Radiation; D013482:Superoxide Dismutase / Q000032:analysis*; D013552:Swine / Q000378:metabolism*; D015032:Zinc / Q000032:analysis
D000596:Amino Acids; D046911:Macromolecular Substances; D003300:Copper; D013482:Superoxide Dismutase; D015032:Zinc