Multistep desolvation as a fundamental principle governing peptide self-assembly through liquid‒liquid phase separation

Biomolecular self-assembly based on peptides and proteins is a general phenomenon encountered in natural and synthetic systems. Liquid‒liquid phase separation (LLPS) is intimately involved in biomolecular self-assembly, yet the key factors at a molecular scale activating or modulating such a process remain largely elusive. Herein, we discovered that multistep desolva-tion is fundamental to the formation and evolution of peptide-rich droplets. The first step is partial desolvation of peptides to form peptide clusters, and the second step is selective desolvation of hydrophobic groups within clusters to trigger LLPS and the formation of peptide-rich droplets, followed by the complete desolvation of droplets, initiating the nucleation of peptide self-assembly. Manipulation of the degree of desolvation at different stages is an effective strategy to control the self-assembly pathways and polymorphisms. This study sheds light on the molecular origin of LLPS-mediated self-assembly dis-tinct from classical one-step self-assembly and paves the way for the precise control of supramolecular self-assembly.