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Ion Mobility Separation of Isomeric Phosphopeptides from a Protein with Variant Modification of Adjacent Residues

Journal Article · · Analytical Chemistry, 83(13):5078-5085
DOI:https://doi.org/10.1021/ac200985s· OSTI ID:1023189

Ion mobility spectrometry (IMS), and particularly differential IMS or field asymmetric waveform IMS (FAIMS), was recently shown capable of separating post-translationally modified peptides with variant PTM localization. However, that work was limited to a model peptide with serine phosphorylation on fairly distant alternative sites. Here, we demonstrate that FAIMS (coupled to ESI/MS) can broadly baseline-resolve variant phosphopeptides from a biologically modified human protein, including those involving phosphorylation of different residues and adjacent sites that existing MS/MS methods are most challenged to distinguish. Singly and doubly phosphorylated variants can be resolved equally well and identified without dissociation, based on accurate separation properties. The results are unchanged over a range of infusion solvent pH, hence present approach should work in conjunction with chromatographic separations using a mobile phase gradient.

Research Organization:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Organization:
USDOE
DOE Contract Number:
AC05-76RL01830
OSTI ID:
1023189
Report Number(s):
PNNL-SA-79163; 34708; KP1601010
Journal Information:
Analytical Chemistry, 83(13):5078-5085, Journal Name: Analytical Chemistry, 83(13):5078-5085 Journal Issue: 13 Vol. 83
Country of Publication:
United States
Language:
English