Designing and analysis of an RNA polymerase model which works under the simulated primitive hot ocean on the earth

RNA世界假说是生命起源的重要原则。然而，从热液生命起源的观点来看，存在一些缺陷。由于RNA是不稳定的，在原始地球条件下不可能出现RNA世界系统。然而，很少有研究来评估这一假设。在这项研究中，一些原始的寡核苷酸形成反应，这些模型是否有可能被用作原始聚合酶模型在水热条件下进行了检查。此外，我们还结合近年来在生命起源和进化方面的理论工作，探讨了RNA世界系统与蛋白质化学进化之间的关系。1.众所周知，在多胞苷酸模板的存在下，活化的鸟苷单体在5 ′-单磷酸鸟苷的磷酸基团上被咪唑修饰，形成寡聚鸟苷酸（TD反应）。氨基乙酸热共聚物的影响 ...更多信息 id的TD反应进行了研究。此外，还研究了氨基酸的影响。2.在水溶性碳二亚胺存在下，具有5 ′-磷酸和3 ′-羟基末端的寡核苷酸发生缩合反应，形成环状寡核苷酸。在0 ~ 75 ℃范围内测定了环化反应的速率常数。根据动力学分析，磷酸二酯键的形成速率可能大于磷酸二酯键的水解速率。因此，我们认为寡核苷酸可能是在原始地球的水热条件下形成的。3.利用水溶性碳二亚胺研究了由胞嘧啶和鸟嘌呤组成的11 - 16聚体寡核苷酸的延伸反应，这些寡核苷酸可能形成发夹结构。研究了HPLC方法来分析这些反应。根据RNA在热液条件下的形成和降解反应行为，推测在原始地球的热液环境中，不可能或很难形成完全由RNA分子组成的RNA体系。这一假设与生命起源的理论著作是一致的。然后，在水热条件下的蛋白质样分子的可能形成模式进行了研究，使用我们的水热流动反应器系统连接的RNA世界和RNA-蛋白质世界。根据这些研究，发现一些寡肽在250-310 ℃下在10-20秒内形成。少

RNA world hypothesis is important as a principle of origin of life. However, there are some drawbacks from the viewpoint of hydrothermal origin of life. Since RNA is labile, it is unlikely that an RNA world system have emerged under the primitive earth conditions. However, there have been few studies carried out to evaluate this assumption. In this study, some primitive formation reactions of oligonucleotides were examined whether these models are possible to be used as primitive polymerase models under hydrothermal conditions. Moreover, the correlation between the RNA world systems and the chemical evolution of proteins were investigated on the basis of our recent theoretical works on the origin and evolution of life.1.It is well known that the activated guanosine monomer, which is modified using imidazole on phospoate group of guanosine 5'-monophosphate, forms oligoguanylate in the presence of a polycytidylic acid template(TD reaction). The influence of thermal copolymers of amino ac … More id to the TD reaction was investigated. In addition, the influence of amino acids was also investigated. Conclusively, it was found that thermal copolymers including histidine and histidine itself inhibited the TD reaction.2.Oligonucleotides which possess 5'-phosphate and 3'-hydroxyl terminals, are condensated to form cyclic oligonucleotides in the presence of water soluble carbodiimide. The rate constants of the cyclization reactions were determined at 0 - 75 ℃. According the kinetic analysis, the rate of the formation of phosphodiester bond could be greater than that of the hydrolysis of phosphodiester bond. Thus, it is strongly assumed that oligonucleotide could have been formed under the hydrothermal conditions on the primitive earth.3.The elongation reactions of 11 - 16-mers oligonucleotides, which consist of cytosine and guanine and are possibly form hairpin structure, were investigated using water soluble carbodiimide. An HPLC method was investigated for the analysis of these reactions. It was confirmed that some elongations occurred under these reactions.4.Based on the reaction behavior of formation and degradation of RNA under hydrothermal conditions, it was deduced that the formation of an RNA system consisting of entirely RNA molecules would have been impossible or difficult under hydrothermal environments on the primitive earth. This assumption is consistent with theoretical works on the origin of life. Then, possible formation models of protein-like molecules under hydrothermal conditions were investigated using our hydrothermal flow reactor system to link the RNA world and the RNA-protein world. Based on these studies, it was discovered that some oligopeptides form at 10-20 sec at 250-310 ℃. Less