Related Experiment Video
Updated: Jun 21, 2026

CD Spectroscopy to Study DNA-Protein Interactions
Published on: February 10, 2022
Identification of spectroscopic patterns of CH...O H-bonds in proteins
1Department of Chemistry & Biochemistry, Utah State University, Logan, Utah 84322-0300, USA. steve.scheiner@usu.edu
Abstract:
Ab initio calculations are used to identify characteristics of vibrational and NMR spectra that signal the involvement of a protein backbone in a CH...O H-bond and that distinguish this sort of interaction from other H-bonds in which a protein might participate. Glycine and alanine dipeptides, in both their C7 and C5 minimum-energy structures, are paired with formamide in a number of different H-bonding arrangements. The CH...O H-bond is characterized by a small contraction of the C-H bond length, along with a blue shift in its stretching frequency, accompanied by an intensification of this vibrational band. In the context of NMR spectra, the bridging CH proton's chemical shift is moved downfield by 1-2 ppm. The aforementioned features are not produced by other H-bonds in which the protein backbone might participate, such as NH proton donation or accepting a proton via the peptide C=O.
More Related Videos
Related Concept Videos
2D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)
IR Spectrum Peak Broadening: Hydrogen Bonding
However, the extent of hydrogen bonding influences the observed stretching frequency and band broadening. Intermolecular or intramolecular hydrogen bonding...
IR Frequency Region: X–H Stretching
¹H NMR Chemical Shift Equivalence: Enantiotopic and Diastereotopic Protons
In chiral compounds such as 2-butanol, replacing the methylene hydrogens at C3 produces a pair of...
IR and UV–Vis Spectroscopy of Aldehydes and Ketones
Spectroscopy of Carboxylic Acid Derivatives
In the...

