College of Chemistry, Xiangtan University, Xiangtan 411105, People's Republic of China; Key Lab of Environment-friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan 411105, People's Republic of China.
College of Chemistry, Xiangtan University, Xiangtan 411105, People's Republic of China.
J Inorg Biochem. 2020 Dec;213:111268. doi: 10.1016/j.jinorgbio.2020.111268. Epub 2020 Oct 6.
The association of two ruthenium(II) complexes [Ru(phen)(o-HPIP)] (Ru1; phen = 1,10-phenanthroline, o-HPIP = 2-(2-hydroxyphenyl)-imidazo[4,5-f][1,10] phenanthroline) and [Ru(phen)(m-HPIP)] (Ru2; m-HPIP = 2-(3-hydroxyphenyl)-imidazo[4,5-f][1,10]phenan- throline) with the RNA poly(U)·poly(A)⁎poly(U) triplex has been investigated by spectrophotometric titrations and melting experiments in this work. All experimental data reveal an intercalative triplex-binding mode of the two complexes, whereas the binding constant for Ru1 is significantly higher than that for Ru2. Circular dichroism spectroscopic investigations show that the two complexes could bind to the chiral environment of the triplex, but the triplex perturbation effects induced by Ru1 are more marked. Thermal denaturation experiments demonstrate that both Ru1 and Ru2 display a large binding preference and stabilizing effect for the third strand over the Watson-Crick base-paired duplex of the triplex. However, the third-strand stabilizing effect of Ru1 is much more effective than that of Ru2. The obtained results suggest that positions of the phenolic group on the main ligands have significant effect on the binding of the two complexes with poly(U)·poly(A)⁎poly(U) triplex.
本文通过分光光度滴定和熔解实验研究了两个钌（II）配合物[Ru(phen)(o-HPIP)]（Ru1；phen = 1,10-邻菲啰啉，o-HPIP = 2-(2-羟基苯基)-咪唑并[4,5-f][1,10]菲啰啉）和[Ru(phen)(m-HPIP)]（Ru2；m-HPIP = 2-(3-羟基苯基)-咪唑并[4,5-f][1,10]菲啰啉）与 RNA 聚（U）·聚（A）⁎聚（U）三聚体的缔合。所有实验数据都表明了两种配合物的嵌入型三聚体结合模式，而 Ru1 的结合常数明显高于 Ru2。圆二色光谱研究表明，两种配合物都可以与三聚体的手性环境结合，但 Ru1 引起的三聚体扰动效应更为明显。热变性实验表明，Ru1 和 Ru2 都对三聚体的第三链具有较大的结合偏好和稳定作用，超过了三聚体的 Watson-Crick 碱基配对双链。然而，Ru1 的第三链稳定作用比 Ru2 更为有效。结果表明，主配体上酚羟基的位置对两种配合物与聚（U）·聚（A）⁎聚（U）三聚体的结合有显著影响。
