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Energetics and structural characterization of isomers using ion mobility and gas‐phase H/D exchange: Learning from lasso peptides
Author(s) -
Hanozin Emeline,
Morsa Denis,
Pauw Edwin
Publication year - 2015
Publication title -
proteomics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.26
H-Index - 167
eISSN - 1615-9861
pISSN - 1615-9853
DOI - 10.1002/pmic.201400534
Subject(s) - chemistry , mass spectrometry , gas phase , ion mobility spectrometry , dissociation (chemistry) , isomerization , fragmentation (computing) , characterization (materials science) , kinetics , energetics , energy landscape , ion , molecular dynamics , computational chemistry , chemical physics , nanotechnology , chromatography , materials science , computer science , thermodynamics , physics , organic chemistry , biochemistry , quantum mechanics , operating system , catalysis
State‐of‐the‐art characterization of proteins using MS namely relies on fragmentation methods that allow exploring featured dissociative reaction pathways. These pathways are often initiated by a series of potentially informative mass‐constant conformational changes that are nonetheless frequently overlooked by lack of adequate investigation techniques. In the present study, we propose a methodology to readily address both structural and energetic aspects of stereoisomerization reactions using ion mobility coupled with MS. To this end, a commercial spectrometer was used as a reactor comprising an energy resolved collisional activation step intended at promoting controlled conformational changes and a structural assignment step dedicated to the identification of the generated isomers. This identification relies on ion mobility and other on‐line coupled techniques, namely an originally designed gas‐phase H/D exchange experiment. We here apply this methodology to characterize the isomerization kinetics of capistruin, a 19‐residue long lasso‐folded peptide. We expect this approach to bring insights into the physical origin of global dissociation thresholds monitored in MS/MS experiments and to set a promising basis for quantitative investigations of the stability of different molecular folds.