Molecular co-evolution on the early Earth. Here, we examine the effect of nucleotides on properties of model protocell systems. We demonstrate that building blocks of nucleic acids, and the lipid type, affect the resulting interactions. Most nucleosides/tides, studied were found to promote and stabilize membranes against prebiotically pertinent stresses, shedding light on potential processes that influenced life's emergence.

Abstract

Spontaneous interactions between nucleotides and lipid membranes are likely to have played a prominent role in the emergence of life on Earth. However, the effect of nucleotides on the physicochemical properties of model protocellular membranes is relatively less understood. To this end, we aimed to discern the effect of canonical nucleotides on the properties of single-chain amphiphile membranes under prebiotically relevant conditions of multiple wet-dry cycles. Furthermore, the change in the critical aggregation concentration of the membranes and their stability in the presence of nucleotides was also investigated in astrobiologically relevant analogue environments. We report that different nucleotides, lipid headgroups, and the ionic makeup of the system affect lipid-nucleotide interactions, and these, in turn, modulate the effect of nucleotides on the membrane properties. Specifically, the presence of AMP, UMP, and CMP promoted self-assembly of oleic acid membranes and increased their stability against certain prebiotically relevant selection pressures. This study takes us a step towards an appreciable understanding of how nucleotides might have shaped the protocellular landscape of the prebiotic Earth.