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Identification of Spectroscopic Patterns of CH--O H-Bonds in Dipeptides
The Journal of Physical Chemistry B (2009)
  • Steve Scheiner, Utah State University

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.

  • identification,
  • spectroscopic,
  • patterns,
  • CH,
  • O,
  • hydrogen bonds,
  • dipeptides
Publication Date
January 1, 2009
Citation Information
Identification of Spectroscopic Patterns of CH--O H-Bonds in Dipeptides S. Scheiner J. Phys. Chem. B 2009 113 10421-10427