Calculation of far-infrared absorption in polymer DNA

Abstract

We calculate the far-infrared absorption of a specific form of DNA polymer—the B conformation, poly(dA)⋅poly(dT)—using eigenvectors from a lattice dynamical model refined with inelastic neutron scattering data. Our various calculations include the isolated helix, the addition of counterions, and the addition of a ‘‘spine of hydration’’ in the minor groove. We find agreement with experimental infrared data except for one mode. We then attempt to model a coupling between two helices and show some evidence that this mode is interhelical.