Abstract:
Two subjects related to the non-equilibrium dynamics of polymers or
biological filaments adsorbed to two-dimensional substrates will be
discussed.
The first part is dedicated to thermally activated dynamics of
polymers on
structured substrates in the presence or absence of a driving force. The
structured substrate is represented by double-well or periodic
potentials.
Both homogeneous and point driving forces are considered. Point-like
driving forces can be realized in single molecule manipulation by atomic
force microscopy tips. Uniform driving forces can be generated by
hydrodynamic flow or by electric fields for charged polymers.
The second part is dedicated to collective filament motion in motility
assays for motor proteins, where filaments glide over a motor-coated
substrate. The model for the simulation of the filament dynamics
contains
interactive deformable filaments that move under the influence of forces
from molecular motors and thermal noise. Motor tails are attached to the
substrate and modeled as flexible polymers (entropic springs), motor
heads perform a directed walk with a given force-velocity relation. I will
consider the collective filament dynamics and pattern formation as a
function of the motor and filament density, the force-velocity
characteristics, the detachment rate of motor proteins and the filament
interaction. In particular, the formation and statistics of filament
patterns such as nematic ordering due to motor activity or clusters
due to
blocking effects are investigated.