Multivalent Diffusive Transport

TL;DR

This paper models multivalent diffusive transport involving a central hub with multiple binding feet, deriving an analytical diffusion coefficient expression to guide experimental design and optimize transport efficiency.

Contribution

It introduces a new model for multivalent diffusive transport and provides an analytical expression for the diffusion coefficient based on simulation data.

Findings

Derived an analytical expression for diffusion coefficient.

Simulated 100 different multivalent transporter designs.

Provided insights into optimizing diffusivity and processivity.

Abstract

We present here a model for multivalent diffusive transport whereby a central point-like hub is coupled to multiple feet, which bind to complementary sites on a two-dimensional landscape. The available number of binding interactions is dependent on the number of feet (multivalency), and on their allowed distance from the central hub (span). Using Monte Carlo simulations that implement the Gillespie algorithm, we simulate multivalent diffusive transport processes for 100 distinct walker designs. Informed by our simulation results we derive an analytical expression for the diffusion coefficient of a general multivalent diffusive process as a function of multivalency, span, and dissociation constant Kd. Our findings can be used to guide experimental design of multivalent transporters, in particular providing insight into how to overcome trade-offs between diffusivity and processivity.