Spectroscopic studies on the interaction between troxerutin and bovine serum albumin

The interaction between troxerutin and bovine serum albumin (BSA) was investigated by fluorescence and absorption spectroscopy under simulative physiological conditions. Results show that troxerutin causes the fluorescence quenching of BSA through a static quenching procedure. The binding constant KA and number of binding sites n of troxerutin with BSA were obtained. Positive values of thermodynamic parameters enthalpy change (ΔH) and entropy change (ΔS) indicate that the interaction between troxerutin and BSA is driven mainly by hydrophobic forces. It seems that the binding is spontaneous at standard state for the change in standard Gibbs free energy (ΔG) value is negative. The binding distance between the donor (BSA) and the acceptor (troxerutin) was calculated to be about 4.21 nm based on the Förster theory. The effect of troxerutin on the conformation of BSA was also analyzed by using synchronous fluorescence spectroscopy.