Peptides at vesicle and mineral prebiotic interfaces

The origin of life likely involved a complex interplay between organic molecules and mineral surfaces, yet the molecular details of these interactions remain poorly understood. Over recent decades, considerable research has focused on the individual roles of key biomolecules—such as RNA, lipids, and proteins—in early abiogenesis. However, this reductionist view offers only a partial picture; the emergence of life likely involved networks of molecular interactions that collectively shaped early functional assemblies. In this study, we examine the potential of peptides—arguably one of the most abundant early polymers—to interact with mineral surfaces and lipid vesicles, prebiotic interfaces and compartments. Focusing on peptide compositions derived from prebiotically plausible amino acids, we demonstrate that early peptides could bind to mineral surfaces (such as fluorapatite studied here) via negatively charged residues and contribute to the release of bioavailable phosphate from geological reservoirs. Nevertheless, the recruitment of amino acids from the modern alphabet was likely adaptive for favourable interactions with lipid vesicles, leading to enhanced vesicle growth and stability. Our findings suggest that while early random peptides could contribute to functionality at geochemical interfaces, the evolving complexity of the peptide/protein alphabet was likely a key factor in the evolution of protocells.