Department of Chemical Biology, Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, Fujian, China.
Institute of Drug Discovery Technology, Ningbo University, 315211, Ningbo, Zhejiang, China.
Chem Asian J. 2022 Dec 14;17(24):e202200926. doi: 10.1002/asia.202200926. Epub 2022 Nov 18.
Short peptides with unique catalytic abilities are regarded as the simplest enzymes possessing great potential as primordial species to take part in the chemical origin of life. However, prebiotic acquisition pathways of catalytically active peptides remain unclear. In this study, a microwave reactor was used to simulate hydrothermal environments, such as hydrothermal vents, either submarine or subaerial environments. A refrigerator freezer was used to make ice pieces that mimic extra-terrestrial ice crystals. Serine (Ser) and histidine (His) were used as examples, and the formation of small functional peptides involving sodium trimetaphosphate (P m) activation in an alkaline aqueous solution was investigated under the two typical prebiotic environments mentioned above. The obtained experimental results showed that the targeted small functional peptide Ser-His and its sequence isomer His-Ser could be formed in all simulated environments, even in the presence of disruptive amino acids, such as alanine (Ala), proline (Pro), and aspartic acid (Asp), in the reaction systems. Notably, Pro may have some effect on the chirality of the produced dipeptides by screening the configuration of the amino acids. Owing to the lack of disturbance of N-O migration in the CAPA (His) intermediate, the CAPA intermediate of His is more stable than that of Ser; therefore, His is more easily activated by P m to form a dipeptide with His at the N-terminal. The yield of His-Ser is at least about four times that of Ser-His in the two simulated prebiotic environments. Additionally, our work suggests that more types of amino acids can be activated simultaneously by P m to produce various dipeptides, which will provide abundant raw materials for the evolution of life molecules.
具有独特催化能力的短肽被认为是最简单的酶，具有作为原始物种参与生命化学起源的巨大潜力。然而，催化活性肽的前生物获取途径仍不清楚。在这项研究中，使用微波反应器模拟了热液环境，如海底或陆上热液喷口。使用冰箱制作模拟外星冰晶的冰块。以丝氨酸（Ser）和组氨酸（His）为例，研究了在上述两种典型的前生物环境下，在碱性水溶液中涉及三聚磷酸钠（P m）激活的小功能肽的形成。实验结果表明，即使在反应体系中存在破坏氨基酸（如丙氨酸（Ala）、脯氨酸（Pro）和天冬氨酸（Asp）），也可以在所有模拟环境中形成目标小功能肽 Ser-His 及其序列异构体 His-Ser。值得注意的是，Pro 可能通过筛选氨基酸的构型对产生的二肽的手性产生一些影响。由于 CAPA（His）中间体中不存在 N-O 迁移的干扰，His 的 CAPA 中间体比 Ser 更稳定；因此，His 更容易被 P m 激活，形成以 His 为 N 端的二肽。在这两种模拟的前生物环境中，His-Ser 的产率至少是 Ser-His 的四倍。此外，我们的工作表明，P m 可以同时激活更多类型的氨基酸来产生各种二肽，这将为生命分子的进化提供丰富的原料。
