Multi-spectroscopic and molecular modeling studies to reveal the interaction between propyl acridone and calf thymus DNA in the presence of histone H1: binary and ternary approaches

DNA is the primary target of many anticancer drugs involved in important intercellular processes, especially in transcriptional regulation, and histone is known to inhibit gene expression. Small molecules can bind to histone-DNA and impair the cell division, growth, inhibition, and apoptosis in cancer cells. In this research, the interaction of a histone H1-calf thymus DNA (ct DNA) complex and propyl acridone (PA) was investigated in Tris-HCl buffer, pH 6.8, using multi-spectroscopic, viscosity, and molecular modeling techniques. The Stern Volmer plot of the (H1-ct DNA) PA complex demonstrated two sets of binding sites with various binding affinities at three different temperatures. Thermodynamic parameters (ΔH° < 0 and ΔS° < 0) indicated that hydrogen bonds and van der Waals forces played the main roles in the binding of the drug to H1-ct DNA. The interaction between PA and ct DNA as well as (H1-ct-DNA) in the presence of acridine orange and ethidium bromide showed two different interaction behaviors in ...