title: The primary structure of human erythrocyte copper/zinc superoxide dismutase: cleavage with Staphylococcus aureus protease, determination of the N-terminal blocking group and location of the disulfide bond.
abstract: Results obtained after digestion of copper/zinc superoxide dismutase from human erythrocytes with S. aureus protease are described. In particular, peptides soluble in alkaline conditions proved essential for completing the determination of the primary structure of the enzyme; other peptides were important for establishing the amidation state of dicarboxylic amino acid residues and for confirming controversial sequences. The human enzyme is acetylated at the NH2 terminus and contains an intrasubunit disulfide bond connecting half-cystine residues 57 and 146.
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002417:Cattle; D003300:Copper / Q000378:metabolism*; D004220:Disulfides / Q000032:analysis; D010450:Endopeptidases / Q000378:metabolism*; D004912:Erythrocytes / Q000201:enzymology*; D006736:Horses; D006801:Humans; D008666:Metalloendopeptidases; D010446:Peptide Fragments / Q000032:analysis; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D013482:Superoxide Dismutase / Q000097:blood*; D015032:Zinc / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D004220:Disulfides; D010446:Peptide Fragments; D003300:Copper; D013482:Superoxide Dismutase; D010450:Endopeptidases; D008666:Metalloendopeptidases; C022653:auR protein, Staphylococcus aureus; D015032:Zinc