Fig. 1: Proposed mechanism for prebiotic polypeptide formation in ice matrices.

a Proposed Mechanism for Prebiotic Polypeptide Formation in Ice Matrices. The schematic illustrates a potential pathway for the formation of prebiotic polypeptides from amino acids in ice (left). (1) Amino acids in dilute aqueous solutions undergo microphase separation in the crystalline ice matrix. (2) Following aggregation, sublimation of ice leads to the enrichment of amino acid clusters. (3) These aggregates facilitate the polymerization of amino acids into more complex polypeptides, possibly under cosmic radiation or other prebiotic conditions. The inset on the right shows a molecular dynamics snapshot of glutamate molecules (blue: nitrogen atom, red: oxygen atom) and SNI (yellow: sulfur atom) interacting with the surface of ice, where SNI (Iodine atoms have been hidden) experiences changes in ground-state conformations. b The bottom panel highlights the observed phosphorescence (Phos.) shifts in SNI from yellow to green upon conformational changes induced by the rotational motion (left) of SNI interacting with the ice surface. This interaction provides spectroscopic evidence for amino acid nanoaggregation of various microphologies (right), a critical step in the proposed mechanism for peptide polymerization in early Earth conditions. (vibronic energy level: v, singlet state: S, triplet state: T).