Identification of phosphotyrosine residues during protein sequence analysis

Abstract

Synthetic tyrosine-phosphorylated peptides were subjected to protein sequence analysis using a gas-phase sequencer and on-line phenylthiohydantoin (PTH) amino acid analysis. Our data show that phosphotyrosine is stable to the gas-phase sequencing chemistry and can be detected as its PTH-derivative during routine sequence analysis without the need of prior tyrosine radiolabeling.