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Gas-phase rearrangements do not affect site localization reliability in phosphoproteomics data sets.

ABSTRACT: Intramolecular transfer of phosphate during collision-induced dissociation (CID) in ion-trap mass spectrometers has recently been described. Because phosphorylation events are assigned to discrete serine, threonine, and tyrosine residues based on the presence of site-determining ions in MS/MS spectra, phosphate transfer may invalidate or confound site localization in published large-scale phosphorylation data sets. Here, we present evidence for the occurrence of this phenomenon using synthetic phosphopeptide libraries, specifically for doubly charged species. We found, however, that the extent of the transfer reaction was insufficient to cause localization of phosphorylation sites to incorrect residues. We further compared CID to electron-transfer dissociation (ETD) for site localization using synthetic libraries and a large-scale yeast phosphoproteome experiment. The agreement in site localization was >99.5 and 93%, respectively, suggesting that ETD-based site localization is no more reliable than CID. We conclude that intramolecular phosphate transfer does not affect the reliability of current or past phosphorylation data sets.

SUBMITTER: Aguiar M

PROVIDER: S-EPMC2912977 | biostudies-literature | 2010 Jun

REPOSITORIES: biostudies-literature

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Gas-phase rearrangements do not affect site localization reliability in phosphoproteomics data sets.

Aguiar Mike M Haas Wilhelm W Beausoleil Sean A SA Rush John J Gygi Steven P SP

Journal of proteome research 20100601 6

Intramolecular transfer of phosphate during collision-induced dissociation (CID) in ion-trap mass spectrometers has recently been described. Because phosphorylation events are assigned to discrete serine, threonine, and tyrosine residues based on the presence of site-determining ions in MS/MS spectra, phosphate transfer may invalidate or confound site localization in published large-scale phosphorylation data sets. Here, we present evidence for the occurrence of this phenomenon using synthetic p ...[more]

PMID: 20377248

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Dataset Information

Gas-phase rearrangements do not affect site localization reliability in phosphoproteomics data sets.

Publications

Gas-phase rearrangements do not affect site localization reliability in phosphoproteomics data sets.

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