Vibrational dynamics of poly(L-tyrosine)

Normal modes and their full dispersions are obtained for the right-handed α-helical poly(l-tyrosine). Optically active modes corresponding to the zone center and at the helical angle are assigned. Both the assignments and the force field are supported by the spectra of N-D species. In addition, modes corresponding to the regions of high density of states and other characteristic features of dispersion curves such as repulsion and exchange of character are discussed. Conformation sensitive modes of other α-helices are compared. Heat capacity is obtained from the dispersion curves via density of states and it is found in agreement with the measured data.