Formation of dityrosine cross-links in proteins by oxidation of tyrosine residues.
1. Enzymic oxidation of proteins with peroxidase and hydrogenperoxide at a basic pH value leads to an oxidative phenolic coupling of adjacent tyrosine residues forming cross-linked proteins. 2. Dityrosine (3,3'-bityrosine) was identified as the cross-link in oxidised proteins by thin-layer chromatography, amino acid analysis and fluorescence measurements. 3. Gel filtration experiments with oxidised insulin showed that the cross-linkage is predominantly intermolecular. 4. In tetranitromethane treated proteins, dityrosine could be identified after hydrolysis.
D000596:Amino Acids / Q000032:analysis; D001665:Binding Sites; D002855:Chromatography, Thin Layer; D006735:Horseradish Peroxidase; D046911:Macromolecular Substances; D010084:Oxidation-Reduction; D010636:Phenols; D011485:Protein Binding; D011506:Proteins; D013050:Spectrometry, Fluorescence; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D014443:Tyrosine / Q000032:analysis*
D000596:Amino Acids; D046911:Macromolecular Substances; D010636:Phenols; D011506:Proteins; D014443:Tyrosine; D006735:Horseradish Peroxidase