The effect of polyvalency on tethered molecular walkers on independent 1D tracks

Abstract

We study the motion of random walkers with residence time bias between first and subsequent visits to a site, as a model for synthetic molecular walkers composed of coupled DNAzyme legs known as molecular spiders. The mechanism of the transient superdiffusion has been explained via the emergence of a boundary between the new and the previously visited sites, and the tendency of the multi-legged walker to cling to this boundary, provided residence time for a first visit to a site is longer than for subsequent visits. Using both kinetic Monte Carlo simulation and an analytical approach, we model a system that consists of uni-pedal walkers, each on its own one-dimensional track, connected by a “tether”, i.e., a kinematic constraint that no two walkers can be more than a certain distance apart. Even though a single uni-pedal walker does not at all exhibit directional, superdiffusive motion, we find that a team of uni-pedal walkers on parallel tracks, connected by a flexible tether, does enjoy a superdiffusive transient. Furthermore, uni-pedal walker teams exhibit a greater expected number of steps per boundary period and are able to diffuse more quickly than bipedal walker teams, which leads to longer periods of superdiffusion.

Type
Publication
Physical Review E, 101, 062101