Modeling Equilibrium Clusters in Lysozyme Solutions

TL;DR

This study combines experiments and simulations to understand how equilibrium clusters form in lysozyme solutions, revealing the balance of forces leading to cluster phases.

Contribution

It introduces a simple effective potential model that accurately describes cluster formation in protein solutions, highlighting the roles of electrostatic repulsion and attraction.

Findings

Cluster phase emerges from competition between repulsion and attraction.

Effective potential model fits X-ray scattering data well.

Long-range Coulomb repulsion and short-range attraction are key factors.

Abstract

We present a combined experimental and numerical study of the equilibrium cluster formation in globular protein solutions under no-added salt conditions. We show that a cluster phase emerges as a result of a competition between a long-range screened Coulomb repulsion and a short-range attraction. A simple effective potential, in which only depth and width of the attractive part of the potential are optimized, accounts in a remarkable way for the wavevector dependence of the X-ray scattering structure factor.