Catalytic Assembly of Peptides Mediated by Complex Coacervates

Area of Science:

• Biomaterials Science
• Supramolecular Chemistry
• Chemical Engineering

Background:

• Peptide assembly is crucial for supramolecular materials, often controlled by liquid-liquid phase separation.
• Modulating phase separation kinetics is key to controlling peptide assembly.
• Complex coacervates offer a novel approach to influence peptide self-assembly.

Purpose of the Study:

• To investigate the catalytic role of complex coacervates in peptide assembly.
• To explore how sodium alginate (SA) and KLVFFAE (KE) peptide interactions affect assembly kinetics.
• To determine the optimal conditions for SA-KE coacervate-mediated peptide assembly.

Main Methods:

• Formation of complex coacervates between negatively charged sodium alginate (SA) and positively charged KLVFFAE (KE) peptide.
• Analysis of peptide assembly kinetics under varying SA-KE binding affinities and SA dosages.
• Characterization of the transition from template-induced to catalytic and spontaneous assembly.

Main Results:

• SA-KE complex coacervates effectively lower the nucleation barrier for peptide assembly.
• Assembly efficiency transitions from inefficient template-induced to highly efficient catalytic assembly as SA dosage decreases.
• An optimal binding affinity and stoichiometry exist for maximizing peptide assembly rates, challenging the 'more is better' assumption.

Conclusions:

• Complex coacervates can act as potent catalysts for peptide self-assembly.
• Peptide assembly kinetics are highly sensitive to the binding affinity and stoichiometry of coacervate components.
• The findings provide a new strategy for controlling the formation of peptide-based supramolecular materials.