After modifying Davydov's original equations for the $\alpha$-helix soliton to include ten additional dipole-dipole coupling terms and to represent helical symmetry, a numerical study predicts that such solitons should appear under normal physiological conditions. This conclusion is supported by the assignment of a recently measured laser-Raman spectrum of a metabolically active cell to internal vibrations of the soliton. Analytical studies of continuum approximations to the numerical model provide additional insight into the soliton dynamics.

• Received 29 October 1981

DOI:https://doi.org/10.1103/PhysRevA.26.578