Prebiotic organization of fatty acids and amino acids in the interface zone between the hydro and lithosphere Original Research Article

Hydrothermal environments as the interface zone between the hydro and lithosphere could have been capable of prebiotically synthesizing various molecules including fatty acids and amino acids. In addition, the complex of fatty acids and amino acids could have further exhibited capability of synthesizing various oligomers or oligopeptides on or inside the lipid vesicles made of fatty acids. We constructed in the laboratory a simulated interface zone between the hydro and lithosphere, and examined the molecular organization that could be synthesized from oleic acid and glycine. The simulated interface zone was maintained between hot and cold water, and the reaction fluid was circulated between the hot and the cold region repeatedly. Glycine was found to adhere on or to be encapsulated into the lipid vesicles made of oleic acid, even though the vesicles were formed and dissolved as traversing the interface zone connecting different temperatures. Synthesis of oligoglycine was enhanced in the presence of the lipid vesicles of oleic acid, compared to the cases otherwise. Furthermore, the temperature of the hot water required for the proper synthesis of oligoglycine could be lowered in the presence of oleic acid vesicles. These observations, when combined together, reveal the fact that lipid vesicles of fatty acids could have been functional in facilitating and accelerating oligomerization of monomers even prior to the evolutionary emergence of phospholipids and the vesicles thereof.