title: Intrinsic folding of small peptide chains: spectroscopic evidence for the formation of beta-turns in the gas phase.
abstract: Laser desorption of model peptides coupled to laser spectroscopic techniques enables the gas-phase observation of genuine secondary structures of biology. Spectroscopic evidence for the formation of beta-turns in gas-phase peptide chains containing glycine and phenylalanine residues establishes the intrinsic stability of these forms and their ability to compete with other stable structures. The precise characterization of local minima on the potential energy surface from IR spectroscopy constitutes an acute assessment for the state-of-the-art quantum mechanical calculations also presented. The observation of different types of beta-turns depending upon the residue order within the sequence is found to be consistent with the residue propensities in beta-turns of proteins, which suggests that the prevalence of glycine in type II and II' turns stems essentially from an energetic origin, already at play under isolated conditions.
authors.affiliation: Laboratoire Francis Perrin (URA CEA-CNRS 2453), Service des Photons, Atomes et Molécules, Centre d'Etudes de Saclay, Bât. 522, 91191 Gif-sur-Yvette Cedex, France.
authors.forename: Wutharath
authors.initials: W
authors.lastname: Chin
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Dognon
authors.forename: François
authors.initials: F
authors.lastname: Piuzzi
authors.forename: Benjamin
authors.initials: B
authors.lastname: Tardivel
authors.forename: Iliana
authors.initials: I
authors.lastname: Dimicoli
authors.forename: Michel
authors.initials: M
authors.lastname: Mons
mesh_terms: D004151:Dipeptides / Q000737:chemistry*; D005740:Gases; D005998:Glycine / Q000737:chemistry*; D010649:Phenylalanine / Q000737:chemistry*; D017510:Protein Folding; D017433:Protein Structure, Secondary; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet
chemical_list: D004151:Dipeptides; D005740:Gases; C040500:phenylalanylglycine; D010649:Phenylalanine; C029660:glycylphenylalanine; D005998:Glycine