Superchaotropic Stabilization of Monomeric Protein States.

Chaotropes are long known to destabilize protein assemblies and folding. We report that a boron cluster ion, as a weakly coordinating superchaotrope, can paradoxically stabilize protein folding even under extended thermal stresses while broadly inhibiting specific and nonspecific protein-protein interactions at millimolar concentrations for multiple proteins. Thermodynamic and kinetic investigations suggest that the boron cluster ion reduced the association rates of protein association and rendered protein-associative interactions entropically unfavorable. The preliminary utility of this phenomenon is demonstrated by the preservation of protein functions within complex mixtures stored in ambient, uncontrolled conditions, boosting their shelf life and stability against aggregation.