RNA as Major Components in Chemical Evolvable Systems

Abstract

A milestone for the origin of life was the onset of a sustained functional interplay between nucleic acids, peptides, lipids and sugars, to form chemical dynamic off-equilibrium systems. The bilayer surface of lipidic vesicles served for the anchoring and enrichment of macromolecules that could grow in size would interact with one another one thousand fold more frequently than unbound in solution and could sooner or later be internalised into the interior of the vesicles. Within a flow of exogenous high-energy compounds, internalised, possibly surface-bound, hereditary molecules like RNA could then grow in population size and length more rapidly, safer and more reliably. When “fed” with activated and activating monomers over a long enough time period, such systems would persist, acquire partial control over their environment and eventually produce replicating protocells capable of autonomously producing high-energy compounds on their own.

We are outlining here how hydrophobic interactions between peptides and lipids can drive supramolecular multicomponent systems including RNA to assemble into models of functionalised protocells that carry potentially inheritable genetic information. Mixing chemically activated macromolecular libraries of synthetic biomolecules with an evolvable population of lipidic giant vesicles is an experimental bottom-up approach being rooted in a growing community of the emergent research area “Systems Chemistry”. The aim of such experimentation is to initiate lifelike behaviour from inanimate chemical systems. The impact of having at one’s disposal chemical protocols for the off-equilibrium search for synthetic peptides that transport synthetic RNA into giant lipidic vesicles (or cells) is difficult to overestimate. On a fundamental level, the impact of being able to prepare “living synthetic cells” would be quite breathtaking.