Entropy driven key-lock assembly

TL;DR

This paper demonstrates that entropy alone can drive the self-assembly of a key-lock pair in a fluid, revealing a potential mechanism for biological assembly processes without the need for attractive forces.

Contribution

It provides a detailed 2D map of the entropic interaction potential and proposes a self-assembling pathway driven solely by entropy, highlighting solvent effects in biological assembly.

Findings

Entropy can induce key-lock self-assembly without attractive forces.

A 2D interaction potential map was constructed from Monte Carlo simulations.

Trajectories avoiding potential barriers enable assembly driven by entropy.

Abstract

The effective interaction between a sphere with an open cavity (lock) and a spherical macroparticle (key), both immersed in a hard sphere fluid, is studied by means of Monte Carlo simulations. As a result, a 2d map of the key-lock effective interaction potential is constructed, which leads to the proposal of a self-assembling mechanism: there exists trajectories through which the key-lock pair could assemble avoiding trespassing potential barriers. Hence, solely the entropic contribution can induce their self-assembling even in the absence of attractive forces. This study points out the solvent contribution within the underlying mechanisms of substrate-protein assembly/disassembly processes, which are important steps of the enzyme catalysis and protein mediated transport.