DYNAMICS OF CYTOSKELETAL FILAMENTS

We apply elasticity theory formalism to study long-range, collective v ibrations of actin and intermediate filaments, which are long cylindri cal macromolecules and constitute part of the cytoskeleton network in eukariotic cells. The dispersion relations are obtained for elastic wa ves propagating in the vicinity of filaments which are modeled as elas tic cylindrical rods immersed in a liquid. In the long-wavelength limi t the filament-water system supports two acoustic modes with propagati on speeds of approximately 800 and 1300 m/s and a single flexural wave with parabolic dispersion law. The presence of solvent leads to radia tion of acoustic energy from waves with a phase velocity exceeding the speed of sound of water. Our study complements the existing normal-mo de analysis of free actin filament vibrations and generalizes these re sults for different structures as well as including the effects of sol vents.