Systems Biophysics, Department of Physics, Ludwig-Maximilians-Universität München, Nanosystems Initiative Munich and Center for NanoScience, Amalienstraße 54, 80799, München, Germany.
Angew Chem Int Ed Engl. 2019 Sep 9;58(37):13155-13160. doi: 10.1002/anie.201907909. Epub 2019 Aug 7.
To understand the emergence of life, a better understanding of the physical chemistry of primordial non-equilibrium conditions is essential. Significant salt concentrations are required for the catalytic function of RNA. The separation of oligonucleotides into single strands is a difficult problem as the hydrolysis of RNA becomes a limiting factor at high temperatures. Salt concentrations modulate the melting of DNA or RNA, and its periodic modulation would enable melting and annealing cycles at low temperatures. In our experiments, a moderate temperature difference created a miniaturized water cycle, resulting in fluctuations in salt concentration, leading to melting of oligonucleotides at temperatures 20 °C below the melting temperature. This would enable the reshuffling of duplex oligonucleotides, necessary for ligation chain replication. The findings suggest an autonomous route to overcome the strand-separation problem of non-enzymatic replication in early evolution.
为了理解生命的出现，更好地了解原始非平衡条件下的物理化学是必不可少的。RNA 的催化功能需要有显著的盐浓度。寡核苷酸分离成单链是一个难题，因为在高温下，RNA 的水解成为限制因素。盐浓度调节 DNA 或 RNA 的熔化，其周期性调制将能够在低温下进行熔化和退火循环。在我们的实验中，适度的温度差异创造了一个微型水循环，导致盐浓度的波动，从而使寡核苷酸在低于熔化温度 20°C 的温度下熔化。这将使双链寡核苷酸重新排列，这对于连接链复制是必要的。研究结果表明，有一种自主途径可以克服早期进化中非酶复制中链分离的问题。
