A systems approach to understanding the emergence of functional protocells

Abstract

Life is thought to have originated from a heterogeneous prebiotic soup, wherein various kinds of simple organic and inorganic molecules interacted, increased molecular complexity, and further evolution led to the emergence of life. A systems chemistry approach is required to elucidate the mechanism of the life-forming process and synthesize in-vitro life. Under such an approach, it becomes necessary to study interactions between various kinds of biomolecules and the emergent properties of the resulting system. Lipids, amino acids and nucleosides are monomers of life's three fundamental and essential polymers. In this study, we studied two pertinent cross-talks, the first being the covalent interaction between nucleosides and single-chain amphiphiles, yielding the formation of nucleolipids. We synthesized single acyl chain-based nucleolipid molecules and characterized their self-assembly property. The second cross-talk studied is the non-covalent interaction between amino acids and model protocellular membranes. Our results show that amino acids assist and promote the self-assembly of model prebiotic membranes. We further show that the amino acid-membrane interaction affects the physicochemical properties of the membrane. Our results demonstrate that amino acid interaction with the membrane might have been crucial for the origin of the protocell and its evolution.