Two-state flashing molecular pump

TL;DR

This paper presents an exactly solvable model of a two-state flashing molecular pump driven by a ratchet mechanism, capable of maintaining particle density gradients across a membrane, with biological relevance.

Contribution

It introduces a novel exactly solvable model of a molecular pump based on flashing ratchet dynamics, linking transition rates to ATP hydrolysis, and explores its energetics within biological parameters.

Findings

The model maintains a steady density gradient across the membrane.

Transition rates are related to ATP binding and hydrolysis.

The energetics of the pump are analyzed and optimized for biological conditions.

Abstract

Here we study a pumping device capable of maintaining a density gradient and a flux of particles across a membrane. Its driving mechanism is based on the flashing ratchet effect powered by the random telegraph process in the presence of thermal fluctuations. Unlike Brownian motors, the concentrations at both reservoir boundaries need to be implemented as boundary conditions. The residence transition rates of the dichotomic flashing are related to the binding and hydrolysis of ATP molecules. The model is exactly solved and explored. The pump energetics is discussed and the relevant parameter values are tuned within a biological scale.