Department of Biophysics, Faculty of Biology, Yerevan State University, Yerevan, Armenia.
Laboratory of Physical Chemistry, Research Institute of Chemistry, Yerevan State University, Yerevan, Armenia.
J Biomol Struct Dyn. 2023;41(24):15320-15327. doi: 10.1080/07391102.2023.2189475. Epub 2023 Mar 15.
To reveal the effect of DNA- or RNA-specific low-molecular compounds on cellular processes on the molecular level, we have carried out the studies with the application of spectroscopic methods. It is necessary for the understanding of structural-functional properties of nucleic acids in cell. In this work the interaction of DNA-specific thiazine dye methylene blue (MB) with synthetic polynucleotides poly(rA) and poly(rU) was studied. The interaction of MB with synthetic polyribonucleotides poly(rA) and poly(rU) was examined in the solution with high ionic strength in a wide phosphate-to-dye (P/D) range, using the absorption and fluorescence spectroscopies, as well as the fluorescence 2D spectra and 3D spectra analyses were given. Values of the fluorescence quenching constants for the complexes of MB with poly(rA) and poly(rU) were calculated (K is the Stern-Volmer quenching constant). Two different modes of MB binding to single-stranded (ss-) poly(rA) and poly(rU) and to their hybrid double-stranded (ds-) structure - poly(rA)-poly(rU) were identified. This ligand binds to ss-poly(rA) and poly(rA)-poly(rU) by semi-intercalation and electrostatic modes, but to ss-poly(rU) the prevailing mode is the electrostatic interaction.Communicated by Ramaswamy H. Sarma.
为了在分子水平上揭示 DNA 或 RNA 特异性低分子化合物对细胞过程的影响，我们应用光谱方法进行了研究。这对于理解细胞中核酸的结构功能特性是必要的。在这项工作中，研究了 DNA 特异性噻嗪染料亚甲蓝 (MB) 与合成多核苷酸聚 (rA) 和聚 (rU) 的相互作用。在高离子强度溶液中，在很宽的磷酸盐与染料 (P/D) 比范围内，使用吸收和荧光光谱以及荧光 2D 光谱和 3D 光谱分析，研究了 MB 与合成聚核糖核苷酸聚 (rA) 和聚 (rU) 的相互作用。计算了 MB 与聚 (rA) 和聚 (rU) 形成复合物的荧光猝灭常数值（K 是 Stern-Volmer 猝灭常数）。确定了 MB 与单链 (ss-) 聚 (rA) 和聚 (rU) 及其杂交双链 (ds-) 结构聚 (rA)-聚 (rU) 结合的两种不同模式。这种配体通过半嵌入和静电模式与 ss-poly(rA) 和 poly(rA)-poly(rU) 结合，但与 ss-poly(rU) 结合的主要模式是静电相互作用。由 Ramaswamy H. Sarma 传达。
