HEAT-CAPACITY AND PHONON-DISPERSION IN POLY(L-METHIONINE)

Poly(L-methionine) (PMet) is one of the two sulfur containing polyamin o acids. Raman, FTIR spectra, and heat capacity measurements of PMet h ave been well interpreted through the normal mode analysis and the den sity of states derived therefrom. Earlier interpretation of heat capac ity data is limited because it is based on the Tarasov model, wherein the concept of group frequency and skeletal similarity are used. A spe cial feature of some dispersion curves is their tendency to bunch in t he neighborhood of the helix angle. This has been attributed to the pr esence of strong intramolecular interactions. Repulsion between the di spersion curves is also observed. (C) 1997 John Wiley & Sons, Inc.