Nonsteady hydrodynamics of biopolymer motions

Many biopolymers undergo conformational fluctuations in which large subunits move relative to each other under the influence of significant mechanical restoring forces. It is shown that nonsteady hydrodynamic effects may be important in the solvent response to such macromolecular motions. This result is in marked contrast to the familiar case of conformational fluctuations of random coil polymers, which move under the influence of weak entropic forces. The nonsteady solvent response is shown to affect the details of the biopolymer motion and to produce special qualitative features in the Raman light scattering spectrum of such macromolecules.