Research Summary
The emergence of life in the prebiotic Earth must have involved the formation of polypeptides, yet the polymerization of amino acids is thermodynamically unfavorable under biologically relevant conditions due to the production of a water molecule via condensation. We hypothesize that atmospheric aerosols catalyzed the prebiotic formation of peptide bonds to form oligopeptides by providing the correct molecular orientations to start the condensation reaction. We have tested this hypothesis using density-functional theory combined with an extensive sampling scheme to sample configurational space. The dimerization of glycine through condensation is spontaneous in the gas phase and increases in spontaneity as catalytic water molecules are added through at least the first ten waters. This increase is driven by the stability of the product clusters which can bend to maximize the intra- and intermolecular binding interactions, specifically hydrogen bonding. We are now working towards establishing lifetimes and activation energies using second order Møller-Plesset perturbation theory.