Continuum dynamics of a peptide chain (Q1371524)

We derive equations for the dynamics of a peptide chain in a ``quadrilateral chip'' model, passing to the continuum from the discrete chain structure and assuming various local interactions. We include the appropriate constraints peculiar to peptides. Dihedral interactions are included and, when strong, are seen to ensure stability. The helices are exact particular solutions of our general equations. In order to obtain eigenfrequencies, a simplified model is introduced and peptide oscillations with frequencies of the order of \(10^{13} s^{-1}\) are obtained, in agreement with observations. Solitons are found in very restricted cases. External forces, such as those due to the solvent, are included in the model.