Structural and Energetic Effects of O2′-Ribose Methylation of Protonated Pyrimidine Nucleosides
Structural and Energetic Effects of O2′-Ribose Methylation of Protonated Pyrimidine Nucleosides
复制标题
质子化嘧啶核苷 O2α-核糖甲基化的结构和能量效应
DOI：
10.1007/s13361-019-02300-9
复制
发表时间：
2019
影响因子：
3.2
通讯作者：
Compagnon, I.
中科院分区：
文献类型：
--
作者：
He, C. C.;Hamlow, L. A.;Zhu, Y.;Nei, Y.-w.;Fan, L.;McNary, C. P.;Maître, P.;Steinmetz, V.;Schindler, B.;Compagnon, I.
2'-取代基将 DNA 与 RNA 核苷区分开来。 2'-O-甲基化自然发生在 RNA 中，在生物过程中发挥重要作用。这种 2'-修饰可能会改变核苷的氢键相互作用，从而可能影响 RNA 链中核苷的构象。通过红外多光子解离 (IRMPD) 作用光谱并辅以电子结构计算来检查质子化 2'-O-甲基化嘧啶核苷的结构。还通过能量分辨碰撞诱导解离 (ER-CID) 检查了质子化 2'-O-甲基化嘧啶核苷 [Nuom+H]+ 的糖苷键稳定性，并与其 DNA 和 RNA 核苷类似物进行比较。 2'-O-甲基化嘧啶核苷的优选质子化位点与其典型的 DNA 和 RNA 核苷类似物 [dNuo+H]+ 和 [Nuo+H]+ 平行，但它们的核碱基方向和糖褶皱不同。质子化嘧啶核苷的糖苷键稳定性遵循以下顺序：[dNuo+H]+<[Nuo+H]+<[Nuom+H]+。结构的轻微改变有助于解释嘧啶核苷 2'-O-甲基化引起的稳定性。
The 2′-substituents distinguish DNA from RNA nucleosides. 2′-O-methylation occurs naturally in RNA and plays important roles in biological processes. Such 2′-modifications may alter the hydrogen-bonding interactions of the nucleoside and thus may affect the conformations of the nucleoside in an RNA chain. Structures of the protonated 2′-O-methylated pyrimidine nucleosides were examined by infrared multiple photon dissociation (IRMPD) action spectroscopy, assisted by electronic structure calculations. The glycosidic bond stabilities of the protonated 2′-O-methylated pyrimidine nucleosides, [Nuom+H]+, were also examined and compared to their DNA and RNA nucleoside analogues via energy-resolved collision-induced dissociation (ER-CID). The preferred sites of protonation of the 2′-O-methylated pyrimidine nucleosides parallel their canonical DNA and RNA nucleoside analogues, [dNuo+H]+and [Nuo+H]+, yet their nucleobase orientation and sugar puckering differ. The glycosidic bond stabilities of the protonated pyrimidine nucleosides follow the order: [dNuo+H]+< [Nuo+H]+< [Nuom+H]+. The slightly altered structures help explain the stabilization induced by 2′-O-methylation of the pyrimidine nucleosides.