The relationship between the tyrosine residue 850-830 cm-1 Raman doublet intensity ratio and the aromatic side chain
Belén Hernández1, Yves-Marie Coïc2, Sergei G Kruglik3
1LVTS, INSERM U1148, 74 rue Marcel Cachin, 93017 Bobigny Cédex, France.
Abstract:
Tyrosine (Tyr) residue in a peptide chain is characterized by the presence of seven Raman markers, referred to as Yi (i = 1, …, 7), distributed over the middle wavenumber spectral region. Particularly, the changes observed in the relative intensity of Y5 and Y6 markers, appearing as a side by side doublet at ca. 850-830 cm-1, has received a great attention. Primarily assigned to a Fermi-resonance effect between phenol ring planar and nonplanar modes, former density functional theory calculations led us to affiliate the Y5-Y6 doublet to two distinct fundamental modes. Furthermore, despite the previous assumptions, it was evidenced that the reversal of the doublet intensity ratio cannot be solely explained by hydrogen bonding on the phenol hydroxyl group involved in Tyr. Herein, upon analyzing the observed and theoretical data collected from the cationic species of the tripeptide Gly-Tyr-Gly, the crucial effect of the aromatic side chain orientation, especially that of the χ1 torsion angle defined around the CαCβ bond, on the Tyr doublet intensity ratio has been evidenced.
More Related Videos
08:54Vibrational Spectra of a N719-Chromophore/Titania Interface from Empirical-Potential Molecular-Dynamics Simulation, Solvated by a Room Temperature Ionic Liquid
Published on: January 25, 2020
08:17Practical Aspects of Sample Preparation and Setup of 1H R1ρ Relaxation Dispersion Experiments of RNA
Published on: July 9, 2021
Related Concept Videos
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations
NMR Spectroscopy of Aromatic Compounds
IR Frequency Region: X–H Stretching
NMR Spectroscopy of Benzene Derivatives
