Probing the interaction of trans-resveratrol with bovine serum albumin: a fluorescence quenching study with Tachiya model.

The interaction of trans-resveratrol (TRES) and bovine serum albumin (BSA) was investigated using fluorescence spectroscopy (FS) with Tachiya model. The binding number maximum of TRES was determined to be 8.86 at 293.15 K, 23.42 at 303.15 K and 33.94 at 313.15 K and the binding mechanism analyzed in detail. The apparent binding constants (K (a)) between TRES and BSA were 5.02 x 10(4) (293.15 K), 8.89 x 10(4) (303.15 K) and 1.60 x 10(5) L mol(-1) (313.15 K), and the binding distances (r) between TRES and BSA were 2.44, 3.01, and 3.38 nm at 293.15, 303.15, and 313.15 K, respectively. The addition of TRES to BSA solution leads to the enhancement in RLS intensity, exhibiting the formation of the aggregate in solution. The negative entropy change and enthalpy change indicated that the interaction of TRES and BSA was driven mainly by van der Waals interactions and hydrogen bonds. The process of binding was a spontaneous process in which Gibbs free energy change was negative.