Reversible reactions controlled by surface diffusion on a sphere

TL;DR

This paper analyzes how reversible binding kinetics influence particle diffusion on spherical surfaces, providing exact solutions and asymptotic formulas relevant for biochemical reactions on cell membranes.

Contribution

It offers the first exact solutions for diffusion with reversible binding on a sphere, highlighting the impact of reversibility on reaction dynamics.

Findings

Reversible binding significantly alters diffusion flux.

Exact expressions for concentration and flux are derived.

Asymptotic formulas are provided for small targets.

Abstract

We study diffusion of particles on the surface of a sphere toward a partially reactive circular target with partly reversible binding kinetics. We solve the coupled diffusion-reaction equations and obtain the exact expressions for the time-dependent concentration of particles and the total diffusive flux. Explicit asymptotic formulas are derived in the small target limit. This study reveals the strong effects of reversible binding kinetics onto diffusion-mediated reactions that may be relevant for many biochemical reactions on cell membranes.