title: Ozone-induced formation of O,O'-dityrosine cross-linked in proteins.
abstract: Treatment of spectrin, insulin, glucagon and ribonuclease with ozone results in covalent cross-linking of these proteins. This cross-linking is not reversed by treatment with dithiothreitol and thus can not be ascribed to -S-S- bond formation. A concomitant O,O'-dityrosine formation is observed by spectrofluorometric analysis of the protein and by amino acid analysis and thin-layer chromatography of hydrolyzed protein samples. It is highly probable that the observed protein cross-linking should be attributed to interpeptide O,O'-dityrosine bonds. Several authors have shown before that oxidation of proteins with horseradish peroxidase and H2O2 also leads to O,O'-dityrosine formation. Peroxidase-induced O,O'-dityrosine formation in galactose oxidase (d-galactose:oxygen 6-oxidoreductase, EC 1.1.3.9) causes a strong increase of enzyme activity. In accordance with these observations ozone treatment of galactose oxidase also leads to O,O'-dityrosine formation with a concomitant 8-fold increase of enzyme activity.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D003432:Cross-Linking Reagents / Q000494:pharmacology; D005692:Galactose Oxidase / Q000378:metabolism; D005934:Glucagon / Q000032:analysis; D006801:Humans; D007328:Insulin / Q000032:analysis; D046911:Macromolecular Substances; D010126:Ozone / Q000494:pharmacology*; D011506:Proteins / Q000032:analysis; D012260:Ribonucleases / Q000032:analysis; D013049:Spectrin / Q000032:analysis; D013050:Spectrometry, Fluorescence; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000032:analysis
chemical_list: D000596:Amino Acids; D003432:Cross-Linking Reagents; D007328:Insulin; D046911:Macromolecular Substances; D011506:Proteins; D013049:Spectrin; D014443:Tyrosine; D010126:Ozone; D005934:Glucagon; C007543:dityrosine; D005692:Galactose Oxidase; D012260:Ribonucleases