Molecular mechanism of protein aggregation inhibition with sulfobetaine polymers and their hydrophobic derivatives

Protein aggregation is a major biomedical challenge necessitating effective protein stabilization strategies. However, the specific interactions between hydrophobic components and proteins in relation to protein aggregation remain poorly understood. Here, we investigate the molecular mechanism of protein aggregation inhibition using zwitterionic polymers, revealing their remarkable efficiency in suppressing protein aggregation. Higher molecular weight and increased hydrophobic modification greatly contribute to near-complete inhibition. Comprehensive investigations employing various techniques unravel weak and reversible interactions between sulfobetaine polymers and proteins, amplified by increasing hydrophobicity and molecular weight. The polymers serve as reversible molecular shields, disrupting the aggregation pathway and impeding the formation of highly aggregation-prone intermediates. Upon stress removal, partially unfolded intermediates regain their native states through refolding. This study represents a comprehensive exploration of protein stabilization with zwitterionic polymers, yielding valuable insights into protein denaturation, the aggregation pathway, and protein-folding dynamics. These findings hold potential for advancing protein therapeutics.