Remdesivir (REM) is an antiviral drug, which exercises its effect by targeting specifically RNA-dependent RNA polymerase. The interaction of REM with calf thymus DNA (CT-DNA) was investigated by multi-spectroscopic techniques (UV–Vis, fluorescence, circular dichroism and ³¹P NMR) in combination with different biophysical experiments and metadynamics simulation studies. UV–Vis and fluorescence spectroscopic analysis indicated formation of a complex between REM and CT-DNA, whose binding constant is in the order of 10⁴ M⁻¹. Competitive displacement assays with ethidium bromide (EB) and Hoechst 33258 shown that REM binds to CT-DNA via intercalation mode. Significant alteration in the band due to base stacking pairs at 274 nm in the circular dichroism spectrum, appreciable increase in relative viscosity of the biomolecule upon binding with REM and the results of potassium iodide quenching studies confirmed that REM intercalates into the base pairs of CT-DNA. Thermodynamic parameters revealed that the binding of REM to CT-DNA is a spontaneous process (ΔG⁰ < 0) and the main force which holds them together in the REM/CT-DNA complex is electrostatic interaction (ΔH⁰ < 0 and ΔS⁰ > 0). The up-field shift in the ³¹P NMR signal of REM on interaction with CT-DNA suggested that phenyl ring adjacent to the phosphate moiety of REM may involve in the intercalation process. This is well supported by the analysis of free energy surface landscape derived from metadynamics simulation studies.

瑞德西韦 (REM) 是一种抗病毒药物，通过特异性靶向 RNA 依赖性 RNA 聚合酶来发挥作用。通过多光谱技术（UV-Vis、荧光、圆二色性和³¹ P NMR）结合不同的生物物理实验和元动力学模拟研究，研究了 REM 与小牛胸腺 DNA（CT-DNA）的相互作用。UV-Vis和荧光光谱分析表明REM和CT-DNA之间形成了复合物，其结合常数约为10 ⁴ M ^-1. 使用溴化乙锭 (EB) 和 Hoechst 33258 进行的竞争性置换分析表明，REM 通过嵌入模式与 CT-DNA 结合。由于圆二色光谱中 274 nm 处的碱基堆叠对导致谱带发生显着变化，与 REM 结合后生物分子的相对粘度显着增加以及碘化钾猝灭研究的结果证实 REM 嵌入 CT-的碱基对中脱氧核糖核酸。热力学参数表明，REM 与 CT-DNA 的结合是一个自发过程（ΔG ⁰  < 0），在 REM/CT-DNA 复合物中将它们结合在一起的主要作用力是静电相互作用（ΔH ⁰  < 0 和 ΔS ⁰  > 0)。³¹中的高场偏移REM与CT-DNA相互作用的P NMR信号表明与REM磷酸基团相邻的苯环可能参与了嵌入过程。来自元动力学模拟研究的自由能表面景观分析很好地支持了这一点。