Characterization of the binding of neomycin/paromomycin sulfate with DNA using acridine orange as fluorescence probe and molecular docking technique

The binding of neomycinsulfate (NS)/ paromomycinsulfate (PS) with DNA was investigated by fluorescence quenching using acridine orange(AO) as a fluorescence probe. Fluorescence lifetime, FT-IR, circular dichroism (CD), relative viscosity, ionic strength, DNA melting temperature, and molecular docking were performed to explore the binding mechanism. The binding constantof NS/PS and DNA was 6.70 × 103/1.44 × 103 L mol−1 at 291 K. The values of ΔHθ, ΔSθ, and ΔGθ suggested that van der Waals forceor hydrogen bond might be the main binding force between NS/PS and DNA. The results of Stern–Volmer plots and fluorescence lifetime measurements all revealed that NS/PS quenching the fluorescence of DNA–AO was static in nature. FT-IR indicated that the interaction between DNA and NS/PS did occur. The relative viscosityand melting temperature of DNA were almost unchanged when NS/PS was introduced to the solution. The fluorescence intensity of NS/PS–DNA–AO was decreased with the increase in the ionic strength. For...