On the interaction of curcumin-samarium coordination and bovine serum albumin

The binding of curcumin-samarium coordination and bovine serum albumin(BSA) was investigated by fluorescence method.According to the fluorescence quenching effect of the complex-BSA,the variable-temperature experiments were finished,from which the binding constants,the number of binding sites and the values of thermodynamic parameters were obtained.The quenching mechanism and the type of binding force were inferred.With the theory of forster energy transfer the distance was calculated.The probe was used for positioning and the synchronous fluorescence spectroscopies were scanned to monitor the effect of the complex on BSA.The results showed that the complex quenched the intrinsic fluorescence of BSA mainly by a static process;meanwhile the non-radiative energy transfer occurred.ΔHθ and ΔSθ0,suggesting van der Waals forces and hydrogen bonding was the main binding force.The binding occurred in the Site Ⅱof BSA molecular and the distance was 2.4 nm.The conformation of BSA molecular was modified by the complex,which had a greater effect on tryptophan residues.