title: Vibrational analysis of amino acids and short peptides in hydrated media. I. L-glycine and L-leucine.
abstract: Raman scattering and Fourier-transform infrared (FT-IR) attenuated transmission reflectance (ATR) spectra of two alpha-amino acids (alpha-AAs), i.e., glycine and leucine, were measured in H2O and D2O (at neutral pH and pD). This series of observed vibrational data gave us the opportunity to analyze vibrational features of both AAs in hydrated media by density functional theory (DFT) calculations at the B3LYP/6-31++G* level. Harmonic vibrational modes calculated after geometry optimization on the clusters containing each AA and 12 surrounding water molecules, which represent primary models for hydration scheme of amino acids, allowed us to assign the main observed peaks.
authors.affiliation: Laboratoire de Spectroscopie Atomique Moléculaire et Applications (LASMA), Département de Physique, Faculté des Sciences de Tunis, Campus Universitaire, 2092 EL MANAR II, Tunisia.
authors.forename: Najoua
authors.initials: N
authors.lastname: Derbel
authors.forename: Belén
authors.initials: B
authors.lastname: Hernández
authors.forename: Fernando
authors.initials: F
authors.lastname: Pflüger
authors.forename: Jean
authors.initials: J
authors.lastname: Liquier
authors.forename: Frédéric
authors.initials: F
authors.lastname: Geinguenaud
authors.forename: Nejmeddine
authors.initials: N
authors.lastname: Jaïdane
authors.forename: Zohra Ben
authors.initials: ZB
authors.lastname: Lakhdar
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Ghomi
mesh_terms: D017666:Deuterium Oxide / Q000737:chemistry; D005998:Glycine / Q000737:chemistry*; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D007930:Leucine / Q000737:chemistry*; D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014867:Water / Q000737:chemistry*
chemical_list: D010455:Peptides; D014867:Water; D007930:Leucine; D017666:Deuterium Oxide; D005998:Glycine