Reconstructing the free-energy landscape associated to molecular motors processivity

TL;DR

This paper develops a biochemical model to describe the free-energy landscape and processivity of molecular motors like kinesin and dynein, incorporating ADP inhibition, and validates predictions with experimental data.

Contribution

It introduces a modified kinetic model including ADP inhibition to reconstruct the free-energy landscape and analytically predict motor velocity and stopping time.

Findings

Reconstructed the free-energy landscape of molecular motor cycles.

Derived analytical expressions for velocity and stopping time.

Predicted collective process durations consistent with experiments.

Abstract

We propose a biochemical model providing the kinetic and energetic descriptions of the processivity dynamics of kinesin and dinein molecular motors. Our approach is a modified version of a well known model describing kinesin dynamics and considers the presence of a competitive inhibition reaction by ADP. We first reconstruct a continuous free-energy landscape of the cycle catalyst process that allows us to calculate the number of steps given by a single molecular motor. Then, we calculate an analytical expression associated to the translational velocity and the stopping time of the molecular motor in terms of time and ATP concentration. An energetic interpretation of motor processivity is discussed in quantitative form by using experimental data. We also predict a time duration of collective processes that agrees with experimental reports.