title: An experimental and theoretical study of the amino acid side chain Raman bands in proteins.
abstract: The Raman spectra of a series of tripeptides with the basic formula GlyAAGly where the central amino acid (AA) was tryptophan, tyrosine, phenylalanine, glycine, methionine, histidine, lysine and leucine were measured in H2O. The theoretical Raman spectra obtained using density functional theory (DFT) calculations at the B3LYP/6-311+G(2df,2pd) level of theory allows a precise attribution of the vibrational bands. The experimental results show that there is a blue shift in the frequencies of several bands of the amino acid side chains in tripeptides compared to free amino acids, especially in the case of AAs containing aromatic rings. On the other hand, a very good agreement was found between the Raman bands of AA residues in tripeptides and those measured on three model proteins: bovine serum albumin, β-lactoglobulin and lysozyme. The present analysis contributes to an unambiguous interpretation of the protein Raman spectra that is useful in monitoring the biological reactions involving AA side chains alteration.
authors.affiliation: Laboratoire Chrono-Environnement, UMR CNRS 6249, Université de Franche-Comté, 16 route de Gray, 25030 Besançon cedex, France.
authors.forename: Béatrice
authors.initials: B
authors.lastname: Sjöberg
authors.affiliation: Laboratoire Chrono-Environnement, UMR CNRS 6249, Université de Franche-Comté, 16 route de Gray, 25030 Besançon cedex, France. Electronic address: sarah.foley@univ-fcomte.fr.
authors.forename: Sarah
authors.initials: S
authors.lastname: Foley
authors.affiliation: Laboratoire Chrono-Environnement, UMR CNRS 6249, Université de Franche-Comté, 16 route de Gray, 25030 Besançon cedex, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Cardey
authors.affiliation: Laboratoire Chrono-Environnement, UMR CNRS 6249, Université de Franche-Comté, 16 route de Gray, 25030 Besançon cedex, France.
authors.forename: Mironel
authors.initials: M
authors.lastname: Enescu
mesh_terms: D000596:Amino Acids / Q000097:blood*; D000818:Animals; D002417:Cattle; D009842:Oligopeptides / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods
chemical_list: D000596:Amino Acids; D009842:Oligopeptides; D011506:Proteins
keywords: Betalactoglobulin; Bovine serum albumin; DFT calculations; Lysozyme; Raman Spectroscopy; Tripeptides