PT Journal
AU Will, A
   Oliinyk, D
   Bleiholder, C
   Meier, F
TI Peptide collision cross sections of 22 post-translational modifications
SO Analytical and Bioanalytical Chemistry: a merger of Fresenius' journal of analytical chemistry and Analusis
PD November
PY 2023
BP 6633
EP 6645
VL 415
IS 27
PU Springer
DI 10.1007/s00216-023-04957-4
WP https://www.db-thueringen.de/receive/dbt_mods_00063291
LA en
DE Post-translational modifications; PTM; Ion mobility; TIMS; Collision cross section; CCS; Chemical Sciences
SN 1618-2642
AB Recent advances have rekindled the interest in ion mobility as an additional dimension of separation in mass spectrometry (MS)-based proteomics. Ion mobility separates ions according to their size and shape in the gas phase. Here, we set out to investigate the effect of 22 different post-translational modifications (PTMs) on the collision cross section (CCS) of peptides. In total, we analyzed ~4300 pairs of matching modified and unmodified peptide ion species by trapped ion mobility spectrometry (TIMS). Linear alignment based on spike-in reference peptides resulted in highly reproducible CCS values with a median coefficient of variation of 0.26%. On a global level, we observed a redistribution in the m/z vs. ion mobility space for modified peptides upon changes in their charge state. Pairwise comparison between modified and unmodified peptides of the same charge state revealed median shifts in CCS between −1.4% (arginine citrullination) and +4.5% (O-GlcNAcylation). In general, increasing modified peptide masses were correlated with higher CCS values, in particular within homologous PTM series. However, investigating the ion populations in more detail, we found that the change in CCS can vary substantially for a given PTM and is partially correlated with the gas phase structure of its unmodified counterpart. In conclusion, our study shows PTM- and sequence-specific effects on the cross section of peptides, which could be further leveraged for proteome-wide PTM analysis. Graphical Abstract
PI Berlin, Heidelberg
ER