TitleEffective discrimination of gas-phase peptide conformers using TIMS-ECD-ToF MS/MS.
Publication TypeJournal Article
Year of Publication2021
AuthorsK Fouque JDit, Wellmann M, D Bombuse L, Santos-Fernandez M, Cintron-Diaz YL, Gomez-Hernandez ME, Kaplan D, Voinov VG, Fernandez-Lima F
JournalAnal Methods
Date Published2021 Nov 11
KeywordsElectrons, Eye, Artificial, Ion Mobility Spectrometry, Peptides, Tandem Mass Spectrometry

In the present work, four, well-studied, model peptides (, substance P, bradykinin, angiotensin I and AT-Hook 3) were used to correlate structural information provided by ion mobility and ECD/CID fragmentation in a TIMS-q-EMS-ToF MS/MS platform, incorporporating an electromagnetostatic cell (EMS). The structural heterogeneity of the model peptides was observed by (i) multi-component ion mobility profiles (high ion mobility resolving power, ∼115-145), and (ii) fast online characteristic ECD fragmentation patterns per ion mobility band (∼0.2 min). Particularly, it was demonstrated that all investigated species were probably conformers, involving /-isomerizations at X-Pro peptide bond, following the same protonation schemes, in good agreement with previous ion mobility and single point mutation experiments. The comparison between ion mobility selected ECD spectra and traditional FT-ICR ECD MS/MS spectra showed comparable ECD fragmentation efficiencies but differences in the ratio of radical (˙)/prime (') fragment species (H˙ transfer), which were associated with the differences in detection time after the electron capture event. The analysis of model peptides using online TIMS-q-EMSToF MS/MS provided complementary structural information on the intramolecular interactions that stabilize the different gas-phase conformations to those obtained by ion mobility or ECD alone.

Alternate JournalAnal Methods
PubMed ID34698320
PubMed Central IDPMC8596503
Grant ListR01 GM134247 / GM / NIGMS NIH HHS / United States
R43 GM122131 / GM / NIGMS NIH HHS / United States
R44 GM122131 / GM / NIGMS NIH HHS / United States