Unambiguous phosphosite localization using electron-transfer/higher-energy collision dissociation (EThcD).
We recently introduced a novel scheme combining electron-transfer and higher-energy collision dissociation (termed EThcD), for improved peptide ion fragmentation and identification. We reasoned that phosphosite localization, one of the major hurdles in high-throughput phosphoproteomics, could also highly benefit from the generation of such EThcD spectra. Here, we systematically assessed the impact on phosphosite localization utilizing EThcD in comparison to methods employing either ETD or HCD, respectively, using a defined synthetic phosphopeptide mixture and also using a larger data set of Ti(4+)-IMAC enriched phosphopeptides from a tryptic human cell line digest. In combination with a modified version of phosphoRS, we observed that in the majority of cases EThcD generated richer and more confidently identified spectra, resulting in superior phosphosite localization scores. Our data demonstrates the distinctive potential of EThcD for PTM localization, also beyond protein phosphorylation.
Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
Christian K
CK
Frese
Houjiang
H
Zhou
Thomas
T
Taus
A F Maarten
AF
Altelaar
Karl
K
Mechtler
Albert J R
AJ
Heck
Shabaz
S
Mohammed
D004579:Electron Transport; D006367:HeLa Cells; D006801:Humans; D013058:Mass Spectrometry; D010766:Phosphorylation