title: Can far-IR action spectroscopy combined with BOMD simulations be conformation selective?
abstract: The combination of conformation selective far-IR/UV double resonance spectroscopy with Born-Oppenheimer molecular dynamics (BOMD) simulations is presented here for the structural characterization of the Ac-Phe-Pro-NH2 peptide in the far-infrared spectral domain, i.e. for radiation below 800 cm(-1). Two conformers have been shown to be present in the experiment, namely a conformer with a γ-turn fold (C7 interaction) and a β-turn fold (C10 interaction). The combined experimental and theoretical work presented here aims to provide spectral features typical of each conformer in this far-IR domain. The simulated BOMD far-IR spectra agree well with the experimental spectra and allow direct assignment of the observed bands. These assignments show that the 400-550 cm(-1) spectral domain is conformer selective, allowing us to distinguish the H-bond signature of the γ-turn from the β-turn.
authors.affiliation: LAMBE CNRS UMR8587, Université d'Evry val d'Essonne, Blvd F. Mitterrand, Bât Maupertuis, 91025 Evry, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Mahé
authors.forename: Sander
authors.initials: S
authors.lastname: Jaeqx
authors.forename: Anouk M
authors.initials: AM
authors.lastname: Rijs
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Gaigeot
mesh_terms: D006860:Hydrogen Bonding; D056004:Molecular Dynamics Simulation; D009842:Oligopeptides / Q000737:chemistry*; D017433:Protein Structure, Secondary; D013055:Spectrophotometry, Infrared
chemical_list: D009842:Oligopeptides