Selection of Amino Acid Chirality Induced by Cyclic Dipeptide Synthesis in Plausible Prebiotic Conditions

Abstract

The biological system uses L-amino acids (L-AAs) to construct peptides. The selection of AA chirality in the prebiotic Earth still remains a mystery. Here we report the intrinsic mechanism of AA chiral selection in the formation of prebiotic proline-containing cyclic dipeptide (DKPs). The DKPs were synthesized by equal amounts of L-AA and D-AA with L-Pro that exhibited a clear preference for D-AA as opposed to L-AA. And surprisingly, the L-AA was preferred over D-AA in the mirror-image system with D-Pro. These results indicate that prebiotic DKPs synthesis has a certain selectivity for AA chirality preceded the biological enzymatic catalysis.

Prebiotic Synthesis of ATP: A Terrestrial Volcanism-Dependent Pathway

“…Recent studies showing the preference for interactions between different oligonucleotides and amino acids [ 86 ], as well as the modified nucleotides which are easier to be ligated [ 87 ], have shed new light on these problems. Moreover, the homochirality of RNA and protein, which is a significant issue in the origin of life, may also be achieved during the replication of RNA and ribozyme catalyzed peptide synthesis [ 88 , 89 , 90 ].…”

Editorial: Mars analogs: Environment, habitability and biodiversity

“…In contrast, Guo et al (2022) showcase that experimental geochemical reactions could lead to the selection of chirality of amino acids under plausible prebiotic conditions. The authors believe that geochemical energy-supported organic complexity may have played a role on the very early Earth.…”