The interaction of blood proteins with brucine.

The features of brucine (BC) binding to two blood proteins, bovine hemoglobin (BHb), and bovine serum albumin (BSA), were investigated via fluorescence, circular dichroism and UV/Vis absorption spectroscopy. The results revealed that BC caused the fluorescence quenching of blood proteins by the formation of BC-protein complex. The corresponding thermodynamic parameters were measured at different temperatures. The process of binding BC molecule on protein was a spontaneous molecular interaction procedure in which entropy increased and Gibbs free energy decreased. Hydrophobic and electrostatic interactions play a major role in stabilizing the complex. The molecular docking has been employed to explore the binding site of the BC in BHb and BSA on the Autodock 4.2. The distances r between BC and protein were calculated to be 4.93 and 5.08 nm for BHb, and BSA, respectively. The effect of BC on the conformation of blood proteins was analyzed using CD, synchronous fluorescence and three-dimensional fluorescence spectra.