title: Investigation of secondary structure elements by IR/UV double resonance spectroscopy: analysis of an isolated beta-sheet model system.
abstract: An isolated beta-sheet model system is investigated in a molecular beam experiment by means of mass- and isomer-selective IR/R2PI double resonance spectroscopy as well as ab initio and DFT calculations. As the exclusive intermolecular assembly, a beta-sheet motif is formed by spontaneous dimerization of two isolated peptide molecules. This secondary structure is produced from the tripeptide model Ac-Val-Tyr(Me)-NHMe without any further environment to form the binding motif which is analyzed by both the characteristic amide A and I vibrations. The experimental and theoretical investigations yield the assignment to an antiparallel beta-sheet model. The result of this detailed spectroscopic analysis on an isolated beta-sheet model indicates that there are intrinsic properties of a beta-sheet structure which can be formed without a solvent or a peptidic environment.
authors.affiliation: Heinrich-Heine Universität Düsseldorf, Institut für Physikalische Chemie I, Universitätsstrasse 26.33.O2, 40225 Düsseldorf, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Fricke
authors.forename: Andreas
authors.initials: A
authors.lastname: Funk
authors.forename: Thomas
authors.initials: T
authors.lastname: Schrader
authors.forename: Markus
authors.initials: M
authors.lastname: Gerhards
mesh_terms: D004151:Dipeptides / Q000737:chemistry; D010455:Peptides / Q000737:chemistry*; D017433:Protein Structure, Secondary; D011789:Quantum Theory; D013055:Spectrophotometry, Infrared / Q000379:methods; D013056:Spectrophotometry, Ultraviolet / Q000379:methods
chemical_list: D004151:Dipeptides; D010455:Peptides; C414029:valyltyrosine