College of Chemistry, Xiangtan University, Xiangtan, 411105, People's Republic of China.
Academic Affairs Office, Xiangtan University, Xiangtan, 411105, People's Republic of China.
J Biol Inorg Chem. 2023 Sep;28(6):559-570. doi: 10.1007/s00775-023-02008-y. Epub 2023 Jul 21.
Two arene ruthenium(II) complexes [η-(CH)Ru(pprip)Cl]PF (Ru1; pprip = 2-(3-phenyl-1H-pyrazol-4-yl)-imidazolo[4,5-f][1,10]phenanthroline) and [η-(CH)Ru(HiiP)Cl]PF (Ru2; HiiP = 2-(indole-3-yl)-imidazolo[4,5-f][1,10]phenanthroline) have been synthesized and characterized in this work. Binding properties of Ru1 and Ru2 with the triplex RNA poly(U)•poly(A)*poly(U) were investigated by spectrophotometry and spectrofluorometry as well as viscosimetry. Analysis of spectroscopic titrations and viscosity measurements show that the two complexes bind with the triplex through intercalation, while the binding affinity for Ru2 toward the triplex is stronger than that for Ru1. Melting experiments indicate that the stabilizing effects of Ru1 and Ru2 toward the triplex differ from each other. Under the conditions used herein, Ru1 only stabilizes the Hoogsteen base-paired strand (third strand) without affecting stabilization of the Watson-Crick base-paired strand (the template duplex) of the triplex, while Ru2 stabilizes both the template duplex and the third strand. Although the two complexes prefer to stabilizing the third strand rather than the template duplex, the third-strand stabilization effect of Ru2 is stronger than that of Ru1. The obtained results of this work reveal that the planarity of the intercalative ligands plays an important role in the triplex stabilization by arene Ru(II) complexes.
本文合成并表征了两个芳基钌（II）配合物[η-(CH)Ru(pprip)Cl]PF（Ru1；pprip=2-(3-苯基-1H-吡唑-4-基)-咪唑并[4,5-f][1,10]菲咯啉）和[η-(CH)Ru(HiiP)Cl]PF（Ru2；HiiP=2-(吲哚-3-基)-咪唑并[4,5-f][1,10]菲咯啉）。通过分光光度法、荧光光谱法和粘度法研究了 Ru1 和 Ru2 与三聚体 RNA 聚（U）•聚（A）*聚（U）的结合性质。光谱滴定和粘度测量分析表明，这两个配合物通过嵌入与三聚体结合，而 Ru2 与三聚体的结合亲和力强于 Ru1。融解实验表明，Ru1 和 Ru2 对三聚体的稳定作用不同。在本文所用的条件下，Ru1 仅稳定 Hoogsteen 碱基配对链（第三链），而不影响三聚体的 Watson-Crick 碱基配对链（模板双链）的稳定，而 Ru2 则稳定模板双链和第三链。尽管这两个配合物更倾向于稳定第三链而不是模板双链，但 Ru2 的第三链稳定作用强于 Ru1。本工作的结果表明，芳基钌（II）配合物与三聚体的结合稳定作用中，嵌入配体的平面性起着重要作用。
