Impact of peptide modifications on the isobaric tags for relative and absolute quantitation method accuracy.

ABSTRACT: In this study, the impact of amino acid modifications on the accuracy of the iTRAQ (isobaric tags for relative and absolute quantitation) method was evaluated. MCF-7 breast cancer cells, cultured in the presence of 17β-estradiol and tamoxifen, were used as a model system. The cells were labeled and analyzed by reversed-phase liquid chromatography and pulsed Q dissociation ion trap tandem mass spectrometry detection. Database searching was performed by using various combinations of amino acid modification allowances, i.e, Lys/Tyr/Cys and amino terminal iTRAQ labeling, Lys methylation, acetylation and carbamylation, and Cys/Met oxidation. Other than the intended Lys/amino terminal iTRAQ labeling, such modifications occur as a result of either enzymatic or sample preparation related reactions

SUBMITTER: Tenga MJ 

PROVIDER: S-EPMC3717298 | biostudies-literature | 2011 Feb

REPOSITORIES: biostudies-literature