Conformation and dynamics of a tethered active polymer chain

The conformational and dynamical properties of a tethered semiflexible polymer chain under tangential active force (fa) are studied by using the Langevin dynamics simulation method. The head of the polymer is fixed near an infinite flat surface at z = 0. The polymer is equilibrated first at fa = 0 and then subjected to the active force. Under the influence of the active force, the polymer is gradually compressed. Specially, for large fa and large bending rigidity (kb), the polymer is buckled into a quasihelical structure rotating around the z axis at the steady state. It is found that both the radius of the quasihelical structure (R) and the angular velocity of the rotation (omega) are nearly independent of the polymer length (N), but show scaling relations with fa and kb, i.e., Roc f -1/3 and omega oc f4/3 b , which are explained by simple dynamical models. Before reaching the steady state, it is further found that the buckling velocity of the polymer is proportional to fa but roughly independent of kb and N, then the buckling time (tb) can be described by a scaling relation tb oc Nfa-1. The underlying mechanism of the buckling process is revealed.

Automated summary

This study investigates the conformational and dynamical properties of a tethered semiflexible polymer chain under tangential active force using Langevin dynamics simulation. The results show that for large active force and bending rigidity, the polymer buckles into a quasihelical structure rotating around the z axis, which is independent of the polymer length but shows scaling relations with the active force and bending rigidity. The study also reveals the underlying mechanism of the buckling process.