作者:Jason E. Hein、Eric Tse、Donna G. Blackmond
DOI:10.1038/nchem.1108
日期:2011.9
The single-handedness of biological molecules is critical for molecular recognition and replication processes and would seem to be a prerequisite for the origin of life. A drawback of recently reported synthetic routes to RNA is the requirement for enantioenriched reactants, which fails to address the puzzle of how the single chirality of biological molecules arose. Here, we report the synthesis of highly enantioenriched RNA precursor molecules from racemic starting materials, with the molecular asymmetry derived solely from a small initial imbalance of the amino-acid enantiomers present in the reaction mixture. Acting as spectators to the main reaction chemistry, the amino acids orchestrate a sequence of physical and chemical amplification processes. The emergence of molecules of single chirality from complex, multi-component mixtures supports the robustness of this synthesis process under potential prebiotic conditions and provides a plausible explanation for the single-handedness of biological molecules before the emergence of self-replicating informational polymers. A drawback of recently reported prebiotic routes to RNA is a requirement for enantioenriched reactants. Here, the presence of a slightly enantioenriched amino acid in the reaction mixture is shown to drive the formation of enantiopure RNA precursors. This provides a plausible scenario in which single-handed biological molecules were formed prior to the emergence of self-replicating informational polymers.
生物分子的单手性对于分子识别和复制过程至关重要,并且似乎是生命起源的先决条件。最近报道的 RNA 合成路线的一个缺点是需要对映体富集的反应物,这无法解决生物分子的单一手性如何产生的难题。在这里,我们报道了从外消旋起始材料合成高度对映体富集的 RNA 前体分子,分子不对称性仅源自反应混合物中存在的氨基酸对映体的微小初始不平衡。作为主要化学反应的旁观者,氨基酸精心策划了一系列物理和化学放大过程。从复杂的多组分混合物中出现的单一手性分子支持了这种合成过程在潜在的生命起源条件下的稳健性,并为自我复制信息聚合物出现之前生物分子的单手性提供了合理的解释。 最近报道的 RNA 益生元途径的一个缺点是需要对映体富集的反应物。在这里,反应混合物中存在稍微对映体富集的氨基酸被证明可以驱动对映体纯 RNA 前体的形成。这提供了一个合理的场景,其中单手生物分子是在自我复制信息聚合物出现之前形成的。