Fluorescence spectroscopic studies on the interaction between a new bismuth(III) Schiff base complex and bovine serum albumin

In this work, the binding interaction between a new bismuth(III) Schiff base complex |[Bi(valen)]Cl·2H2O}[H2valen=N,N'-bis(2-hydroxy-3-methoxyphenylmethylidene)-2,6-pyridinediamine, C21H19N3O4] and bovine serum albumin(BSA) was studied via fluorescence quenching method. The static quenching constant KLB and some thermodynamic parameters(e.g., ΔGθ, ΔHθ and ΔSθ) of the interaction were estimated. In particular, the binding site between the complex and BSA was explored by molecular docking. On the basis of the mechanism of Förster energy transfer, the binding distance between the bismuth(III) Schiff base complex and BSA(Trp.213) as well as the transfer efficiency was obtained. Furthermore, the effect of the bismuth(III) Schiff base complex on the con-formation of BSA was investigated using synchronous fluorescence spectroscopy.