A comparison study on the interaction of hyperoside and bovine serum albumin with Tachiya model and Stern-Volmer equation.

The interaction between hyperoside and bovine serum albumin (BSA) was examined by fluorescence spectroscopy at 298, 304, and 310K. The spectroscopic data were analyzed using Tachiya model and Stern-Volmer equation to determine the binding sites and apparent binding constant between hyperoside and BSA. For Tachiya model, both binding sites and apparent binding constants increased with the increasing of temperature, whereas for Stern-Volmer equation, the corresponding binding constants decreased as temperature increasing and the binding sites were independent of temperature. The positive sign of enthalpy change (DeltaH) and entropy change (DeltaS) suggested that hydrophobic forces played a major role in the interaction. Synchronous fluorescence spectra indicated that the conformation of protein was perturbed by the interaction of hyperoside with BSA. Moreover, the presence of metal ion affected the hyperoside-BSA binding.