Assigning Structures to Gas-Phase Peptide Cations and Cation-Radicals. An Infrared Multiphoton Dissociation, Ion Mobility, Electron Transfer, and Computational Study of a Histidine Peptide Ion
| Autor: | Jonathan P. Williams, Béla Paizs, Matthew F. Bush, Julia Chamot-Rooke, Benjamin J. Bythell, Christopher L. Moss, Keith Richardson, Iain Campuzano, František Tureček, Edith Nicol, Jeffery Mark Brown |
|---|---|
| Přispěvatelé: | Department of Chemistry, University of Washington, affiliation inconnue, Laboratoire des mécanismes réactionnels (DCMR), École polytechnique (X)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Waters Corp, German Cancer Research Center - Deutsches Krebsforschungszentrum [Heidelberg] (DKFZ) |
| Rok vydání: | 2012 |
| Předmět: |
Spectrophotometry
Infrared Ab initio Analytical chemistry Infrared spectroscopy Molecular Dynamics Simulation 010402 general chemistry Tandem mass spectrometry 01 natural sciences Dissociation (chemistry) Ion Electron Transport Electron transfer Materials Chemistry Histidine Infrared multiphoton dissociation Physical and Theoretical Chemistry Ions Chemistry 010401 analytical chemistry 0104 chemical sciences Surfaces Coatings and Films [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry Thermodynamics Physical chemistry Density functional theory Gases Peptides |
| Zdroj: | Journal of Physical Chemistry B Journal of Physical Chemistry B, American Chemical Society, 2012, 116 (10), pp.3445-3456. ⟨10.1021/jp3000784⟩ |
| ISSN: | 1520-5207 1520-6106 |
| Popis: | International audience; Infrared multiphoton dissociation (IRMPD) spectroscopy, using a free-electron laser, and ion mobility measurements, using both drift-cell and traveling-wave instruments, were used to investigate the structure of gas-phase peptide (AAHAL + 2H)(2+) ions produced by electrospray ionization. The experimental data from the IRMPD spectra and collisional cross section (Ω) measurements were consistent with the respective infrared spectra and Ω calculated for the lowest-energy peptide ion conformer obtained by extensive molecular dynamics searches and combined density functional theory and ab initio geometry optimizations and energy calculations. Traveling-wave ion mobility measurements were employed to obtain the Ω of charge-reduced peptide cation-radicals, (AAHAL + 2H)(+●), and the c(3), c(4), z(3), and z(4) fragments from electron-transfer dissociation (ETD) of (AAHAL + 2H)(2+). The experimental Ω for the ETD charge-reduced and fragment ions were consistent with the values calculated for fully optimized ion structures and indicated that the ions retained specific hydrogen bonding motifs from the precursor ion. In particular, the Ω for the doubly protonated ions and charge-reduced cation-radicals were nearly identical, indicating negligible unfolding and small secondary structure changes upon electron transfer. The experimental Ω for the (AAHAL + 2H)(+●) cation-radicals were compatible with both zwitterionic and histidine radical structures formed by electron attachment to different sites in the precursor ion, but did not allow their distinction. The best agreement with the experimental Ω was found for ion structures fully optimized with M06-2X/6-31+G(d,p) and using both projection approximation and trajectory methods to calculate the theoretical Ω values. © 2012 American Chemical Society |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|