Interaction between deferiprone and human serum albumin: multi-spectroscopic, electrochemical and molecular docking methods.

The interactions between deferiprone (DEP) and human serum albumin (HSA) have been investigated systematically by fluorescence, Circular dichroism (CD) spectroscopy, UV-Vis absorption spectroscopy, electrochemistry and molecular modeling methods. The fluorescence quenching observed is attributed to the formation of a complex between HSA and DEP, and the reverse temperature effect of the fluorescence quenching has been found and discussed. The thermodynamic parameters, enthalpy changes (ΔH) and entropy change (ΔS) were calculated, according to the Van't Hoff equation. These data suggested that hydrophobic interaction was the predominant intermolecular forces stabilizing the complex, which was in good agreement with the results of molecular modeling study. The primary binding pattern is determined by hydrophobic interaction occurring in Sudlow's site I of HSA. DEP could slightly change the secondary structure and induce unfolding of the polypeptides of protein. An average binding distance of ∼2.88 nm has been determined on the basis of the Förster's resonance energy theory (FRET).