Semiflexibility speeds up the translocation of polymers

The process of polymer translocation (PT) through narrow pores is essential for a number of biological systems. Here, we investigate an unforced PT of a single polymer and of multiple polymers through a pore in two dimensions using the Langevin-dynamics simulations using a coarse-grained bead–spring model. We aim to investigate under which conditions ”stacking” multiple polymers inside a pore facilitates their cooperative PT. The results show that increasing the bending stiffness κ of a single polymer slows down the PT process by reducing the configurational freedom and inhibiting the tension propagation along the chain. In contrast, when two polymers occupy the pore simultaneously, their bending stiffness can speed up the PT. Two flexible polymers translocate faster than a single flexible chain due to ”entropic pushing”, while two semiflexible polymers increasingly prefer the same-side PT as their stiffness increases. In ”mixed” situations of a simultaneous PT of a flexible and a semiflexible polymer, the semiflexible chain consistently translocates faster due to reduced entropic trapping and more efficient tension propagation. These findings demonstrate that bending stiffness, which typically limits the single-PT dynamics, can counterintuitively enhance the cooperative transport in the multiple-polymers scenarios. This can provide new insights into the peculiarities of the PT in a number of systems featuring biological channels or synthetic nanopores.