The influence of hydrodynamic screening near a surface on the dynamics of a
single semiflexible polymer is studied by means of Brownian dynamics
simulations and hydrodynamicmean field theory. The polymer motion is
characterized in terms of the mean squared displacements of the end-monomers,
the end-to-end vector, and the scalar end-to-end distance. In order to control
hydrodynamic screening effects, the polymer is confined to a plane at a fixed
separation from the wall. When gradually decreasing this separation, a
crossover from Zimm-type towards Rouse (free-draining) polymerdynamics is
induced. However, this crossover is rather slow and the free-draining limit is
not completely reached—substantial deviations from Rouse-like dynamics are
registered in both simulations and theory—even at distances of the polymer
from the wall on the order of the monomer size. Remarkably, the effect of
surface-induced screening of hydrodynamic interactions sensitively depends on
the type of dynamic observable considered. For vectorial quantities such as
the end-to-end vector, hydrodynamic interactions are important and therefore
surface screening effects are sizeable. For a scalar quantity such as the end-
to-end distance, on the other hand, hydrodynamic interactions are less
important, but a pronounced dependence of dynamic scaling exponents on the
persistence length to contour length ratio becomes noticeable. Our findings
are discussed against the background of single-molecule experiments on f-actin
[L. Le Goff et al., Phys. Rev. Lett.89, 258101
(2002)]10.1103/PhysRevLett.89.258101
