Oxidation of Tyrosine-Phosphopeptides by Titanium Dioxide Photocatalysis.
Protein phosphorylation has a key role in cell regulation. Oxidation of proteins, in turn, is related to many diseases and to aging, but the effects of phosphorylation on the oxidation of proteins and peptides have been rarely studied. The aim of this study was to examine the mechanistic effect of phosphorylation on peptide oxidation induced by titanium dioxide photocatalysis. The effect of phosphorylation was compared between nonphosphorylated and tyrosine phosphorylated peptides using electrospray tandem mass spectrometry. We observed that tyrosine was the most preferentially oxidized amino acid, but the oxidation reaction was significantly inhibited by its phosphorylation. The study also shows that titanium dioxide photocatalysis provides a fast and easy method to study oxidation reactions of biomolecules, such as peptides.
Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki , P.O. Box 56, Viikinkaari 5E, FI-00014 Helsinki, Finland.
Miina
M
Ruokolainen
Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki , P.O. Box 56, Viikinkaari 5E, FI-00014 Helsinki, Finland.
Elisa
E
Ollikainen
Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki , P.O. Box 56, Viikinkaari 5E, FI-00014 Helsinki, Finland.
Tiina
T
Sikanen
Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki , P.O. Box 56, Viikinkaari 5E, FI-00014 Helsinki, Finland.|Department of Chemistry, University of Helsinki , P.O. BOX 55, A.I. Virtasen aukio 1, FI-00014 Helsinki, Finland.
Tapio
T
Kotiaho
Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki , P.O. Box 56, Viikinkaari 5E, FI-00014 Helsinki, Finland.
Risto
R
Kostiainen
D002384:Catalysis; D017665:Hydroxyl Radical / Q000737:chemistry; D010084:Oxidation-Reduction; D010748:Phosphopeptides / Q000737:chemistry*; D010766:Phosphorylation; D014025:Titanium / Q000737:chemistry* / Q000528:radiation effects; D014443:Tyrosine / Q000737:chemistry*; D014466:Ultraviolet Rays
D010748:Phosphopeptides; C009495:titanium dioxide; D017665:Hydroxyl Radical; D014443:Tyrosine; D014025:Titanium