Introduction

Disaggregation and solubilization of protein aggregates in mild reagents is challenging. Most disaggregation protocols call for protein denaturation in harsh reagents such as detergents, concentrated guanidine-HCl, or 8M urea. Pressure can also be used to denature proteins, and high hydrostatic pressure has shown promise as a means of solubilizing and/or refolding insoluble aggregates due to its effects on electrostatic and hydrophobic interactions – two key components of aggregate formation [2-3]. Disaggregation by pressure works in manner similar to chemical disaggregation, with one significant advantage; pressure-disaggregated proteins do not require extensive clean-up to remove the high concentrations of denaturing chemicals required by conventional methods.Here we report that solubilization of aggregated β-Casein can be enhanced when carried out under high pressure, even in the absence of strong chaotropes. The goal of this work is to provide the user with the best set of starting conditions for pressure-enhanced solubilization of β-Casein or similar aggregated proteins.