Interactions of a Ruthenium-Ketoprofen Compound with Human Serum Albumin and DNA: Insights from Spectrophotometric Titrations and Molecular Docking Calculations

The compound [Ru2O(keto)(2)(py)(6)](PF6)(2), keto=ketoprofen and py=pyridine, interacts with calf thymus-DNA with K-b=1.08x10(4) M-1. It efficiently quenches HSA fluorescence in different temperatures, with Ksv values in the 10(4)-10(5) M-1 range, both by dynamic and static mechanisms. The data provided by the double logarithmic and van't Hoff approximations indicated a moderate (K-b approximate to 10(4) M-1) and spontaneous (Delta G<0) interaction, being enthalpically driven (Delta H=-27.1 kJ mol(-1) and Delta S=-5.3 J mol(-1) K-1). Molecular docking calculations confirmed that the binuclear compound interacts with HSA more strongly than with DNA. The occurrence of a high contribution from electrostatic forces was observed, fully consistent with the bicationic nature of [Ru2O(keto)(2)(py)(6)](PF6)(2). The molecular docking results also revealed that the interaction occurs in an external subdomain, explaining the lack of significant conformational changes in the protein, as probed by circular dichroism spectra.

Automated summary

This study found that the compound [Ru2O(keto)(2)(py)(6)](PF6)(2) interacts with both DNA and HSA, with a stronger interaction with HSA. The interaction occurs mainly through a static mechanism and is enthalpically driven. The molecular docking results also support these observations.