Catalytic Assembly\nof Peptides Mediated by Complex\nCoacervates

The assembly of peptides is generally\nmediated by liquid–liquid\nphase separation, which enables control over assembly kinetics, final\nstructure, and functions of peptide-based supramolecular materials.\nModulating phase separation can alter the assembly kinetics of peptides\nby changing solvents or introducing external fields. Herein, we demonstrate\nthat the assembly of peptides can be effectively catalyzed by complex\ncoacervates. The negatively charged sodium alginate (SA) can form\ncomplex coacervates with the positively charged KLVFFAE (Aβ<sub>16–22</sub>, abbreviated as KE) peptide, thereby lowering\nthe nucleation barrier and promoting the assembly of the peptide.\nAs the binding affinity of SA-KE and the dosage of SA decrease, the\nsystem shifts from a relatively inefficient template-induced assembly\nto a highly efficient catalytic assembly before ultimately reverting\nto slow spontaneous assembly. Therefore, both the affinity as well\nas the stoichiometry do not follow the intuitive rule that “more\nis better”, but rather there exists an optimal value that maximizes\nthe rate of assembly.