ELASTIC VIBRATIONS OF MICROTUBULES IN A FLUID

We study theoretically vibrational properties of microtubules (MTs), w hich are long hollow cylindrical macromolecules with a diam. of the or der of 25 nm and serve as a major component of cytoskeleton in eukario tic cells. Modeling MTs by thin elastic cylindrical shells, we derive the eigenfrequencies and eigenmodes of confined elastic vibrations in a shell-fluid system. Numerical calculations, based on recently obtain ed experimental data for Young's modulus of MT, show that MT-water sys tem supports interface elastic waves with maximal frequencies in a gig ahertz range. In a long-wavelength limit, there exist three axisymmetr ic acoustic waves with velocities of about 200 to 600 m/s, and an infi nite set of helical waves with a parabolic dispersion law.