School of Physics and Optoelectronic Engineering, Ludong University, Yantai 264025, China.
Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States.
J Chem Theory Comput. 2023 Feb 28;19(4):1322-1332. doi: 10.1021/acs.jctc.2c01277. Epub 2023 Feb 8.
RNA strand cleavage by 2'-O-transphosphorylation is catalyzed not only by numerous nucleolytic RNA enzymes (ribozymes) but also by hydroxide or hydronium ions. In experiments, both cleavage of the 5'-linked nucleoside and isomerization between 3',5'- and 2',5'-phosphodiesters occur under acidic conditions, while only the cleavage reaction is observed under basic conditions. An path-integral approach for simulating kinetic isotope effects is used to reveal the reaction mechanisms for RNA cleavage and isomerization reactions under acidic conditions. Moreover, the proposed mechanisms can also be combined through the experimental pH-rate profiles.
2'-O-转磷酸化导致的 RNA 链断裂不仅由众多的核酶(核酸酶)催化,也由氢氧根离子或氢离子催化。在实验中,酸性条件下不仅会发生 5'-连接核苷酸的断裂,还会发生 3',5'-和 2',5'-磷酸二酯键之间的异构化,而碱性条件下仅观察到断裂反应。本研究采用路径积分方法模拟动力学同位素效应,揭示酸性条件下 RNA 断裂和异构化反应的反应机制。此外,通过实验 pH-速率曲线也可结合提出的反应机制。