Heated gas bubbles enrich, crystallize, dry, phosphorylate and encapsulate prebiotic molecules

Abstract

Non-equilibrium conditions must have been crucial for the assembly of the first informational polymers of early life-by supporting their formation and continuous enrichment in a long-lasting environment. Here we explored how gas bubbles in water subjected to a thermal gradient, a likely scenario within crustal mafic rocks on the early Earth, drive a complex, continuous enrichment of prebiotic molecules. RNA precursors, monomers, active ribozymes, oligonucleotides, and lipids are shown to (1) cycle between dry and wet states, enabling the central step of RNA phosphorylation, (2) accumulate at the gas-water interface to drastically increase ribozymatic activity, (3) condense into hydrogels, (4) form pure crystals, and (5) encapsulate into protecting vesicle aggregates that subsequently undergo fission. These effects occurred within less than 30 minutes. The findings unite physical conditions in one location which were crucial for the chemical emergence of biopolymers.They suggest that heated microbubbles could have hosted the first cycles of molecular evolution.Life is a non-equilibrium system. By evolution, modern life has created a complex protein machinery to maintain the nonequilibrium of crowded molecules inside dividing vesicles. Based on entropy arguments, equilibrium conditions were unlikely to trigger the evolutionary processes during the origin of life 1 . External non-equilibria had to be provided for the accumulation, encapsulation, and replication of the first informational molecules. They can locally reduce entropy, give rise to patterns 2 , and lean the system towards a continuous, dynamic self-organization 3 . Non-equilibrium dynamics can be found in many fluid systems, including gravity-driven instabilities in the atmosphere 4 , the accumulation of particles in nonlinear flow 5,6 , and shear-dependent platelet activation in blood 7 . Our experiments discuss whether gas-water interfaces in a thermal gradient could have provided such a nonequilibrium setting for the emergence of life on early Earth.Non-equilibrium systems in the form of heat flows were a very common and simplistic setting, found ubiquitously on the planet 8 . Hydrothermal activity is considered abundant on early Earth and intimately linked to volcanic activity 9 . Water is thereby circulating through the pore space of the volcanic rocks, which is formed by magmatic vesiculation (primary origin) and fractures (secondary origin). These systems have been studied as non-equilibrium driving forces for biological molecules in a variety of processes 10-17 .Gases originating from degassing of deeper magma bodies percolate through these water-filled pore networks. At shallow depths bubbles are formed by gases dissolved in water and formation of vapor where sufficient heat is supplied by the hydrothermal system. The bubbles create gas-water interfaces, which previously have been discussed in connection with atmospheric bubble-aerosol-droplet cycles 18 , the adsorption of lipid monolayers and DNA to the interface 19,20 , or the formation of pep...

Protein-free division of giant unilamellar vesicles controlled by enzymatic activity

“…To the best of our knowledge, we demonstrate for the first time that the division of GUVs can be regulated by metabolic activity. Our results prompt to ask whether similar mechanisms may have sustained cell division at the onset of live [26,27]. Similarly, remnants thereof may still play a role in cell biology today, e.g.…”

Nucleic Acid Catalysis under Potential Prebiotic Conditions

“…The resulting environment up-concentrates av ariety of components including RNA precursors and oligonucleotides, enabling a compelling variety of prebiotically important processes including precursor crystallization and phosphorylation. [207] Furthermore, the same environments ubstantially improves ribozyme catalysis ande ncapsulation within lipid vesicles.T he improved ribozyme catalysis is primarily the result of local high magnesium and RNA concentrationsa tt he air-water interface, but dehydration may also be significant.…”

“…Wet‐dry cycles can also be produced by the application of thermal gradients at an air–water interface (Figure ). The resulting environment up‐concentrates a variety of components including RNA precursors and oligonucleotides, enabling a compelling variety of prebiotically important processes including precursor crystallization and phosphorylation . Furthermore, the same environment substantially improves ribozyme catalysis and encapsulation within lipid vesicles.…”

“… Schematic of a heated rock pore. Thermal gradients at an air–water interface can result in an environment which up‐concentrates a variety of components including ribozymes and ions . The improved ribozyme catalysis is most likely the result of local high magnesium and RNA concentrations at the interface.…”

“…Thermal gradients at an airwater interface can result in an environmentwhich up-concentrates av ariety of components including ribozymes and ions. [207] The improved ribozyme catalysis is most likely the result of local high magnesiuma nd RNA concentrationsatt he interface. However,d irect dehydrationo ft he RNA at the temporallyd ried interfaceo nt he warm side (red) may also contribute to activity.…”