Characteristic of salvianolic acid binding to bovine serum albumin and structure-performance relationship / 中草药

ABSTRACT

Objective To study the characteristic of salvianolic acid(SA) binding to bovine serum albumin(BSA) and the structure-performance relationship.Methods The interactions between BSA and four natural SA(SAⅠ,rosmaric acid;SAⅡ,lithosperic acid;SAⅢ,salvianolic acid A;and SAⅣ,salvianolic acid B) were investigated by fluorescence and ultraviolet spectroscopy.Results The intrinsic fluorescence of BSA was quenched by SA via forming SA-BSA complexes and non-radiation energy transfer.The parameters of SA-BSA binding process,such as the static apparent association constant KA,the number of binding site n,the efficiency of energy transfer E,the spatial distance r were obtained,and the thermodynamic constants ?G,?H,and ?S were calculated.Conclusion The results indicate that SAⅢ bounds to BSA mainly through a hydrophobic force and the other three SA-BSA interactions are mainly driven by hydrogen bond and Van der Waals' force.Y,a comprehensive binding parameter constructing from the equation Y=lg (KA?E?n/r),could be used to reflect the interaction extent of SA-BSA system.The Y value changes with the number of free phenolic hydroxyl and molecule volume and decreases in the order of SAⅢ→SAⅣ→SAⅡ→SAⅠ.The results from correlation analysis indicate that it could be possible to estimate SA-BSA binding extent from hydrophobic parameter clogP and topo-polar surface area per unit of molecular weight tPSA/Mr of SA molecule.