Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991, Moscow, Russia.
Eur Biophys J. 2024 Feb;53(1-2):47-56. doi: 10.1007/s00249-023-01696-3. Epub 2024 Jan 13.
G-quadruplex (G4) structures formed by the guanine-rich DNA regions exhibit several distinctive optical properties, including UV absorption and circular dichroism spectra. Some G4 DNA possess intrinsic UV fluorescence whose origin is not completely clear to date. In this work, we study the effect of TMPyP4 and Methylene Blue on the intrinsic fluorescence of the dimeric G4 DNA structure formed by two d(GT) sequences. We demonstrate that binding of the ligands results in quenching of the intrinsic fluorescence, although the conformation of the G4 DNA and its dimeric structure remain preserved. The binding sites of the ligands were suggested by the photoinduced oxidation of guanines and analysis of binding isoterms. We discuss how DNA-ligand complexes can affect the intrinsic fluorescence of G4 DNA.
G-四链体（G4）结构由富含鸟嘌呤的 DNA 区域形成，表现出多种独特的光学性质，包括紫外吸收和圆二色性光谱。一些 G4 DNA 具有固有紫外荧光，其起源迄今尚不完全清楚。在这项工作中，我们研究了 TMPyP4 和亚甲蓝对由两个 d(GT)序列形成的二聚 G4 DNA 结构固有荧光的影响。我们证明，尽管 G4 DNA 的构象及其二聚体结构保持不变，但配体的结合导致固有荧光猝灭。通过鸟嘌呤的光诱导氧化和结合等温线分析，推测出了配体的结合位点。我们讨论了 DNA-配体复合物如何影响 G4 DNA 的固有荧光。
