A microcalorimetry and spectroscopy study on the interaction of BSA with 2,2'-bipyridine octylglycinato palladium(II) nitrate.

The interaction of bovine serum albumin (BSA) with a new palladium(II) complex [Pd(bpy)(Oct-Gly)]NO(3) (bpy, 2,2 -bipyridine; Oct-Gly, octyl-glycine) was studied by isothermal titration UV-visible spectrophotometry and microcalorimetry in 30 mmol/L Tris buffer, pH 7.0. There is a set of 18 binding sites for this complex on BSA at 300 and 310 K with positive cooperativity in the binding process. The Hill coefficients at 300 and 310 K are 2.2 and 2.4, respectively. The binding of this palladium complex on BSA is endothermic with mean association binding constant of 21.0 and 16.4 (mmol/L) (-1) at 300 and 310 K, respectively. The complex can denature the protein as surfactants. The stability of BSA in the interaction study with the complex is 84 and 58 kJ/mol at 300 and 310 K, respectively. Also, the enthalpy of BSA denaturation due to the interaction with the complex is 842 kJ/mol.