Cooperative transitions involving hydrophobic polyelectrolytes

Hydrophobic polyelectrolytes (HPEs) can solubilize bilayer membranes, form micelles, or can reversibly aggregate as a function of pH. The transitions are often remarkably sharp. We show that these cooperative transitions occur by a competition between two or more conformational states and can be explained within the framework of Monod- Wymann-Changeux (MWC) theory that was originally formulated for allosteric interactions. Here, we focus on the pH-dependent destabilization and permeation of bilayer membranes by HPEs. We formulate the general conditions that lead to sharp conformational transitions involving simple macromolecules mediated by concentration variations of molecular ligands. That opens up potential applications ranging from medicine to the development of switchable materials.

Automated summary

Hydrophobic polyelectrolytes (HPEs) can solubilize bilayer membranes, form micelles, or reversibly aggregate with pH changes. These cooperative transitions can be explained using Monod- Wymann-Changeux (MWC) theory, originally formulated for allosteric interactions. In this study, we focus on the pH-dependent destabilization and permeation of bilayer membranes by HPEs and present general conditions for sharp conformational transitions mediated by concentration variations of molecular ligands. This opens potential applications in fields such as medicine and switchable materials.