| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1195204 | Journal of the American Society for Mass Spectrometry | 2009 | 8 Pages |
Two orders of magnitude matrix-assisted laser desorption/ionization (MALDI) signal enhancement of phosphopeptides has been achieved by picolinamidination of N-terminal amine group and ε-amine group of lysine residues. Due to the presence of picolinamidination tag at the N-terminal amine of peptides, MS/MS spectra with a strong b-ion series was obtained, which greatly facilitated sequencing and identification of the phosphorylation site. Phosphorylation site of a phosphopeptide could be identified from MALDI TOF/TOF spectrum obtained from a tryptic or a chymotryptic phosphopeptide, which was not even detected in the positive ion mode, without signal enhancement by picolinamidination, due to the negative charge of the phosphate group in the presence of other peptides.
Graphical AbstractPicolinamidination of phosphopeptide significantly enhances MALDI signal and facilitates MS/MS sequencing and identification of the phosphorylation site.Figure optionsDownload full-size imageDownload high-quality image (143 K)Download as PowerPoint slide
