Institute of Organic Chemistry, Leibniz University Hannover, Schneiderberg 1B, 30167, Hannover, Germany.
Chemistry. 2022 Oct 4;28(55):e202201419. doi: 10.1002/chem.202201419. Epub 2022 Jul 28.
α-Amino acids are essential molecular constituents of life, twenty of which are privileged because they are encoded by the ribosomal machinery. The question remains open as to why this number and why this 20 in particular, an almost philosophical question that cannot be conclusively resolved. They are closely related to the evolution of the genetic code and whether nucleic acids, amino acids, and peptides appeared simultaneously and were available under prebiotic conditions when the first self-sufficient complex molecular system emerged on Earth. This report focuses on prebiotic and metabolic aspects of amino acids and proteins starting with meteorites, followed by their formation, including peptides, under plausible prebiotic conditions, and the major biosynthetic pathways in the various kingdoms of life. Coenzymes play a key role in the present analysis in that amino acid metabolism is linked to glycolysis and different variants of the tricarboxylic acid cycle (TCA, rTCA, and the incomplete horseshoe version) as well as the biosynthesis of the most important coenzymes. Thus, the report opens additional perspectives and facets on the molecular evolution of primary metabolism.
α-氨基酸是生命的基本分子成分，其中 20 种是特权的，因为它们是由核糖体机制编码的。为什么是这个数量，为什么特别是这 20 种，这是一个几乎哲学上的问题，无法得出明确的结论。它们与遗传密码的演变密切相关，以及核酸、氨基酸和肽是否同时出现，并在地球出现第一个自给自足的复杂分子系统之前的前生物条件下可用。本报告重点介绍从陨石开始的氨基酸和蛋白质的前生物和代谢方面，然后介绍在合理的前生物条件下形成的包括肽在内的氨基酸，以及生命各个王国的主要生物合成途径。辅酶在本分析中起着关键作用，因为氨基酸代谢与糖酵解和不同变体的三羧酸循环（TCA、rTCA 和不完整的马蹄形版本）以及最重要的辅酶的生物合成有关。因此，该报告为初级代谢的分子进化开辟了更多的视角和方面。
