title: Reduced anion binding and anion inhibition in Cu, Zn superoxide dismutase chemically modified at lysines without alteration of the rhombic distortion of the copper site.
abstract: The spectroscopic binding constant (visible absorption and EPR spectra) and the catalytic inhibition constant of N-3 and CN- were measured for bovine Cu, Zn superoxide dismutase chemically modified at all lysines by either succinylation or carbamoylation. These modifications partially inactivate the enzyme (10% and 50% residual activity respectively) but leave the native rhombic geometry of the copper site unaffected. It could thus be shown that the observed reduction of anion affinity of the lysines-modified proteins is related to the decreased positive charge of the protein.
mesh_terms: D000818:Animals; D000838:Anions / Q000097:blood / Q000494:pharmacology*; D001665:Binding Sites / Q000187:drug effects; D002417:Cattle; D003300:Copper / Q000097:blood / Q000494:pharmacology*; D004563:Electrochemistry; D004578:Electron Spin Resonance Spectroscopy; D004912:Erythrocytes / Q000201:enzymology*; D008239:Lysine; D013482:Superoxide Dismutase / Q000037:antagonists & inhibitors*; D015032:Zinc / Q000494:pharmacology
chemical_list: D000838:Anions; D003300:Copper; D013482:Superoxide Dismutase; D015032:Zinc; D008239:Lysine