A growing number of out-of-equilibrium systems have been created and investigated in chemical laboratories over the past decade. One way to achieve this is to create a reaction cycle, in which the forward reaction is driven by a chemical fuel and the backward reaction follows a different pathway. Such dissipative reaction networks are still relatively rare, however, and most non-enzymatic examples are based on the carbodiimide-driven generation of carboxylic acid anhydrides. In this work, we describe a dissipative reaction network that comprises the chemically fueled formation of phosphoramidates from natural ribonucleotides (e.g., GMP or AMP) and phosphoramidate hydrolysis as a mild backward reaction. Because the individual reactions are subject to a multitude of interconnected parameters, the software-assisted tool “Design of Experiments” (DoE) was a great asset for optimizing and understanding the network. One notable insight was the stark effect of the nucleophilic catalyst 1-ethylimidazole (EtIm) on the hydrolysis rate, which is reminiscent of the action of the histidine group in phosphoramidase enzymes (e.g., HINT1). We were also able to use the reaction cycle to generate transient self-assemblies, which were characterized by dynamic light scattering (DLS), confocal microscopy (CLSM), and cryogenic transmission electron microscopy (cryo-TEM). Because these compartments are based on prebiotically plausible building blocks, our findings may have relevance for origin-of-life scenarios.

中文翻译：

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通过计算机辅助设计优化的核糖核苷酸↔氨基磷酸酯反应网络


在过去的十年中，化学实验室创建并研究了越来越多的非平衡系统。实现这一目标的一种方法是创建一个反应循环，其中正向反应由化学燃料驱动，反向反​​应遵循不同的途径。然而，这种耗散反应网络仍然相对罕见，并且大多数非酶促例子都是基于碳二亚胺驱动的羧酸酐的生成。在这项工作中，我们描述了一个耗散反应网络，其中包括由天然核糖核苷酸（例如 GMP 或 AMP）以化学方式促进的氨基磷酸酯的形成以及作为温和逆反应的氨基磷酸酯水解。由于各个反应受到大量相互关联的参数的影响，因此软件辅助工具“实验设计”(DoE) 是优化和理解网络的重要资产。一个值得注意的见解是亲核催化剂 1-乙基咪唑 (EtIm) 对水解速率的明显影响，这让人想起磷酸酰胺酶（例如 HINT1）中组氨酸基团的作用。我们还能够利用反应循环生成瞬态自组装体，其特征在于动态光散射（DLS）、共焦显微镜（CLSM）和低温透射电子显微镜（cryo-TEM）。由于这些区室基于生命起源前的合理构建模块，因此我们的发现可能与生命起源场景相关。