NORMAL-MODES OF POLY(L-VALINE) IN RELATION TO SPECTRA OF OLIGOVALINES

Poly(L-valine) (PLV) belongs to the class of polyamino acids having a bulky side chain. It preferably adopts beta-sheet conformation, althou gh high molecular weight PLV may form an alpha helix as well. In the p resent communication we report a detailed study of the phonons and the ir dispersion for beta-PLV and the spectra of oligovalines in relation to its polymeric form. The N-deuterated analog of beta-PLV has also b een studied to confirm the correctness of assignments and force-field. Density-of-states and heat capacity have been obtained. The heat capa city is in very good agreement with the experimental measurements of R oles et al.