The interaction of transresveratrol (TRES) with bovine serum albumin (BSA) has been investigated by ultraviolet-visible,\r\nfluorescence, Fourier transform infrared spectroscopic methods and molecular modeling techniques. The fluorescence results\r\nshow that the intrinsic fluorescence of BSA is quenched by TRES through a static quenching procedure. The binding constants\r\nof TRES with BSA at 292, 297 and 302K are calculated as 10.22 Ã?â?? 104, 8.71 Ã?â?? 104, and 7.59 Ã?â?? 104 Lmol-1, respectively, and\r\ncorresponding numbers of binding sites are approximately equal to unity.The thermodynamic parameters ?H and ?S are estimated\r\nto be -21.82 kJmol-1 and .15 Jmol-1 K-1, which indicates that the interaction of TRES with BSA is driven mainly by hydrophobic\r\nforces and there are also hydrogen bonds and electrostatic interactions. The competitive experiments suggest that the binding site\r\nof TRES to BSA is probably located on site II. The results of infrared spectra show that the binding of TRES with BSA leads to\r\nconformational changes of BSA, and the binding stabilizes the ??-helix and ??-sheet at the cost of a corresponding loss in the ??-turn\r\nstructure of BSA. The results of molecular modeling calculation clarify the binding mode and the binding sites which are in good\r\naccordance with the experiment results.
Loading....