%A Z Ahmed
%A NS Myshakina
%A SA Asher
%J Journal of Physical Chemistry B
%T Dependence of the AmII'p proline Raman band on peptide conformation
%X We utilized UV resonance Raman (UVRR) measurements and density functional theory (DFT) calculations to relate the AmII'p frequency to the ? angle. The AmII'p frequency shifts by ? 25 cm-1 as the ? angle is varied over allowed angles of the Pro peptide bond. The AmII'p frequency does not show any significant dependence on the ? dihedral angle. The conformation sensitivity of the AmII'p frequency derives from conformation-induced changes in the planarity of the Pro peptide bond; ? angle changes push the amide nitrogen out of the peptide bond plane. We use this AmII'p frequency dependence on the ? angle to track temperature-induced conformation changes in a polyproline peptide. The temperature-induced 7 cm -1 downshift in the AmII'p frequency of the polyproline peptide results from an ?45? rotation of the ? dihedral angle from ? = 145? (ideal PPII conformation) to ? = 100? (collapsed PPII conformation). ? 2009 American Chemical Society.
%N 32
%P 11252 - 11259
%V 113
%D 2009
%R 10.1021/jp809857y
%L pittir17231