The origin of vibrational mode couplings in various secondary structural motifs of polypeptides

  • Moran A
  • Mukamel S
  • 62


    Mendeley users who have this article in their library.
  • 90


    Citations of this article.


Electrostatic (through-space) and covalent (through-bond) contributions to couplings involving the C[double bond]O and C[bond]N vibrational stretching modes of the amide group in the alpha-helix and the parallel and antiparallel beta-sheet structures of alanine polypeptides are analyzed. Coupling constants computed at the density functional theory level are compared with the transition dipole coupling model and the complete electrostatic interaction between transition densities. We find that the transition densities of C[double bond]O modes are localized, and the electrostatic mechanism then holds. In contrast, the C[bond]N mode transition densities are delocalized, and covalent contributions to the coupling are significant.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document


  • A. Moran

  • S. Mukamel

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free