VIBRATIONAL DYNAMICS OF POLY(L-TYROSINE)

Normal modes and their full dispersions are obtained for the right-han ded alpha-helical poly(L-tyrosine). Optically active modes correspondi ng 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 sp ecies. 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 se nsitive modes of other alpha-helices are compared. Heat capacity is ob tained from the dispersion curves via density of states and it is foun d in agreement with the measured data.