Institute of Chemical Biology, Henan University, Kaifeng 475004, China.
The Key Laboratory of Natural Medicine and Immuno-Engineering, Henan University, Kaifeng 475004, China.
J Photochem Photobiol B. 2017 Apr;169:27-34. doi: 10.1016/j.jphotobiol.2017.02.015. Epub 2017 Feb 27.
The interaction between anthracenyl-methyl homospermidine conjugate (ANTMHspd) with herring sperm DNA was investigated by UV/vis absorption, fluorescent spectra, circular dichroism (CD) spectroscopy and HNMR under physiological conditions (pH=7.4). The observed hypochromism effect and fluorescence quenching of ANTMHspd by DNA, and the displacement of EB from DNA-EB system by ANTMHspd suggested that ANTMHspd might interact with DNA by the combined mode of intercalation and groove binding. Further fluorescent tests at different temperatures revealed that the quenching mechanism was a static type. The quenching constant, binding constant and thermodynamic parameter obtained from fluorescence showed that the type of interaction force included mainly hydrogen bonding and van der Waals, which promoted the binding process. The CD test revealed that ANTMHspd could cause the B to A-like conformational change while ANTMHspd is not a typical DNA intercalator. The H NMR tests showed that ANTMHspd partially intercalated DNA. The effect of NaCl and KI on ANTMHspd-DNA interaction provided additional evidences of intercalation. Molecular docking simulation was carried out and the docking model in silico suggested that the binding modes of ANTMHspd and DNA were groove binding and intercalation, with the anthracene moiety inserted in DNA base pairs and the polyamine chain embedded in the DNA groove.
在生理条件（pH=7.4）下，通过紫外/可见吸收、荧光光谱、圆二色性（CD）光谱和 HNMR 研究了蒽基-甲基同 spermidine 缀合物（ANTMHspd）与鲱鱼精子 DNA 的相互作用。观察到 DNA 对 ANTMHspd 的减色效应和荧光猝灭，以及 ANTMHspd 从 DNA-EB 体系中置换 EB，表明 ANTMHspd 可能通过嵌入和沟结合的联合模式与 DNA 相互作用。在不同温度下进行的进一步荧光测试表明，猝灭机制是静态型的。荧光得到的猝灭常数、结合常数和热力学参数表明，相互作用力的类型主要包括氢键和范德华力，这促进了结合过程。CD 测试表明，ANTHspd 可以引起 B 到 A 样构象变化，而 ANTMHspd 不是典型的 DNA 嵌入剂。H NMR 测试表明，ANTMHspd 部分嵌入 DNA。NaCl 和 KI 对 ANTMHspd-DNA 相互作用的影响提供了嵌入的额外证据。进行了分子对接模拟，计算机模拟的对接模型表明，ANTHspd 和 DNA 的结合模式是沟结合和嵌入，蒽部分插入 DNA 碱基对，多胺链嵌入 DNA 沟中。
