Prebiotic adsorption of GABA on Ca-Montmorillonite clay

Adsorption processes of amino acids on clay surfaces are of interest in Origins of Life studies. This is not only since they could have played a role in later surface-catalysed polymerisation processes, but also in themselves, could have possibly changed the chemical environment and/or introduced selectivity in prebiotic systems.

GABA (gamma-aminobutyric acid) is a biological, non-proteinogenic amino acid. It is found in CM meteorites in comparable amounts to that of glycine, the simplest and most common amino acid. GABA is also a minor product of Urey-Miller type synthesis.
Montmorillonite is an abundant layered clay mineral, highly relevant to Origins of Life research. It has a relatively high surface area, can reversibly swell upon hydration and readily adsorb organics on its outer and interlayer surfaces. It is presumed to have existed in the Hadean era on Earth and has been found on Mars.
In a warm little pond scenario on a rocky planet, where hypothetically, a meteorite landed and released some of its’ organic content, GABA might have been present alongside other organics, together with Montmorillonite clay.
In this presentation, results from an experimental adsorption study of GABA on Calcium-Montmorillonite clay, will be shown and discussed.