Proliferating droplets formed via prebiotic polymerisation: the missing link between chemistry and biology on the origin of life

Abstract

The hypothesis that prebiotic molecules were transformed into polymers that evolved into proliferating molecular assemblages and eventually a primitive cell was first proposed about a hundred years ago. However, no proliferating model prebiotic system has yet been realised because different conditions are required for polymer generation and self-assembly of polymers. In this study, we identified conditions suitable for concurrent peptide generation and self-assembly, and we showed how a proliferating peptide-based droplet could be created by using synthesised amino acid thioesters as prebiotic monomers. Oligopeptides generated from the monomers spontaneously formed droplets through liquid–liquid phase separation in water. The droplets underwent a steady growth–division cycle by periodic addition of monomers through autocatalytic self-reproduction. Heterogeneous enrichment of RNA and lipids within droplets enabled RNA to protect the droplet from dissolution by lipids. These results provide experimental platforms for origin-of-life research and open up novel directions in peptide-based material development.