On-Line Liquid Chromatography Electron Capture Dissociation for the Characterization of Phosphorylation Sites in Proteins
Electron capture dissociation (ECD) allows fragmentation of the phosphopeptide backbone while keeping the labile phospho-amino acid intact. This feature of ECD fragmentation, coupled with the acquisition of mass spectra at high mass accuracy, makes ECD well-suited to phosphorylation mapping. The following methods are designed to focus ECD events on phosphopeptides within a complex peptide sample, either by using phosphoric acid neutral loss peaks as a trigger or by targeted analysis of predetermined precursor masses.
Key wordsECD Neutral loss Phosphorylation FT-ICR LTQ-FT Xcalibur Site localization AGC Targeted OMSSA
We are grateful to Lewis Geer for assistance with the OMSSA algorithm for ECD. This work was funded by the EU (FP6 Endotrack; www.endotrack.org) (SMMS) and the Wellcome Trust (074131) (HJC).
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