Dityrosine formation is impaired by tyrosine phosphorylation.
Using pure tyrosine and phosphotyrosine we have recently shown that phosphotyrosine is unable to form peroxidase catalyzed dimers (1989, FEBS Lett. 255, 395-397). In the present report, the effect of phosphotyrosine residues within a protein structure on dityrosine formation was studied using casein as a model protein. Dephosphorylation of casein resulted in a dose and time dependent increased synthesis of dityrosines following treatment with peroxidase/H2O2. The extent of crosslink formation was inversely related to the amount of phosphorylated tyrosine residues as quantitated by immunoblotting. Thus, phosphorylation of tyrosine residues could play a regulatory role in protein-crosslinking where dityrosine bonds are involved.
Christian
S
S
Institute of Medical Chemistry, University of Vienna, Austria.
Bernhard
G
G
Patrizia
R
R
Brigitte
M
M
D000469:Alkaline Phosphatase / Q000378:metabolism; D000911:Antibodies, Monoclonal; D002364:Caseins / Q000378:metabolism*; D006735:Horseradish Peroxidase / Q000378:metabolism*; D007700:Kinetics; D019000:Phosphotyrosine; D013050:Spectrometry, Fluorescence; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism
D000911:Antibodies, Monoclonal; D002364:Caseins; D019000:Phosphotyrosine; D014443:Tyrosine; C007543:dityrosine; D006735:Horseradish Peroxidase; D000469:Alkaline Phosphatase