基于15N标记研究远古海洋中核苷对L-/D-氨基酸成肽的调控作用

氨基酸的手性起源和肽的前生源（生命出现之前）合成是生命起源研究的关键问题。众所周知，肽的生物合成是L-氨基酸以mRNA（其基本组成单元为核苷）为模板按一定顺序经脱水缩合而成，但生物体利用L-氨基酸这一手性是如何起源的机制尚不明确。氨基酸的手性起源研究主要集中在氨基酸手性对称性是如何被打破的，但至今尚未取得令人信服的进展。近年来，基于肽的前生源合成，研究氨基酸的手性起源日益受到重视。我们前期研究发现，通过模拟远古海洋条件，在前生源肽合成过程中，核苷可以影响氨基酸的成肽量。因此推测氨基酸手性起源可能是通过核苷调控前生源L-/D-氨基酸形成肽的过程而实现的。本项目拟模拟远古海洋条件，基于15N同位素标记、液质联用和核磁共振等技术，研究在前生源肽合成过程中，核苷对L-/D-氨基酸手性选择的调控作用并探讨其可能机制，为氨基酸手性起源的实验研究提供新线索。

The origin of amino acid homochirality and prebiotic peptide synthesis are key issues concerning the origin of life. It is well known that ribosomal peptides are biosynthesized via the dehydration condensation of L-amino acids under the sequence mRNA template. However, the mechanism of the L-amino acids homochirality origin in living systems is still unknown. Many studies focused on the amino acids chiral symmetry breaking, but no convincing achievements have been reported. Recently, the study of the amino acids homochirality origin based on prebiotic peptide synthesis has received increasing attentions. Our previous studies on the prebiotic peptide synthesis from amino acids under simulated Hadean marine conditions revealed that the yields of peptide are related with the nucleosides. Therefore, we proposed that the origin of amino acid homochirality is effected by the regulation of nucleosides on the prebiotic L-/D-amino acid-forming peptide process. In this project, we proposed to study the chiral regulation of nucleosides on the prebiotic peptide synthesis under simulating Hadean marine conditions based on 15N isotope labeling, LC-MS and NMR technology. We also aim to provide new evidences for the amino acid homochirality origin by probing into the regulation mechanism.