A plausible pathway to prebiotic peptides via amino acid amides on the primordial Earth

The prebiotic synthesis of peptides prior to ribosome-catalyzed processes remains an enigma.The synthesis of abiotic peptides from amino acids(AAs)is primarily constrained by high activation energies and unfavorable thermodynamics,necessitating the identification of plausible prebiotic alternatives for synthesizing prebiotic peptides.Here we present a plausible pathway to the formation of prebiotic peptides,wherein oligopeptides,oligopeptide amides,and cyclic oligopeptides can be directly synthesized from amino acid amides(AA-NH2)under wet–dry cycle conditions without the need for any enhancers.The subsequent investigation revealed that AA-NH2 demonstrated more favorable thermodynamic reaction effects than AAs in peptide formation.In contrast to the polymerization of AAs,the process of peptide formation through the polymerization of AA-NH2 was significantly simplified.Additionally,AA-NH2 was discovered to function as a“bridge”for the formation of peptides from AAs,thereby facilitating their participation in the synthesis of intricate peptide structures.On the basis of these findings,a plausible mechanism for the prebiotic origin network of peptides under primordial Earth conditions has been proposed.Overall,this research presents a plausible pathway for the generation of prebiotic peptides and peptide libraries within prebiotic environments.

The sequence-dependent morphology of self-assembly peptides after binding with organophosphorus nerve agent VX

VX is a highly toxic organophosphorus nerve agent that the Chemical Weapons Convention classifies as a Schedule 1. In our previous study, we developed a method for detecting organophosphorus compounds using peptide self-assembly. Nevertheless, the self-assembly mechanisms of peptides that bind organophosphorus and the roles of each peptide residue remain elusive, restricting the design and application of peptide materials. Here, we use a multi-scale computational combined with experimental approach to illustrate the self-assembly mechanism of peptide-bound VX and the roles played by residues in different peptide sequences. We calculated that the self-assembly of peptides was accelerated after adding VX, and the final size of assembled nanofibers was larger than the original one, aligning with experimental findings. The atomic scale details offered by our approach enabled us to clarify the connection between the peptide sequences and nanostructures formation, as well as the contribution of various residues in binding VX and assembly process. Our investigation revealed a tight correlation between the number of Tyrosine residues and morphology of the assembly. These results indicate a self-assembly mechanism of peptide and VX, which can be used to design functional peptides for binding and hydrolyzing other organophosphorus nerve agents for detoxification and biomedical applications.