Binding mechanism of halide ions to bovine serum albumin and hemoglobin: investigated by ion selective-electrode

Gongke Wang, Wen Tang, Xiaoxiao Hao, Changling Yan, Yan Lu
2011 Journal of Biophysical Chemistry  
The binding mechanism of the interactions of halide ions (F -, Brand I -) with bovine serum albumin (BSA) and hemoglobin (Hb) were studied at different temperatures, by using ion-selective electrodes. The experimental data were treated according to Klotz equation, and the number of binding sites and the binding constants were determined. The results show that the binding sites of Fon protein molecules are more than those of Brand I -. Additionally, the number of the binding sites for halide
more » ... ites for halide ions on protein molecules increases with increasing temperature. This study also indicates that the binding constants for the interactions of halide ions with proteins gradually decrease as the size of halide ions and temperature increases. These behaviors were reasonably interpreted with the structural and thermodynamic factors. The thermodynamic functions at different temperatures were calculated with thermodynamic equations, and the enthalpy change for the interactions were also determined by isothermal titration calorimetry (ITC) at 298.15 K, which indicate that the interactions of halide ions with proteins are mainly electrostatic interaction.
doi:10.4236/jbpc.2011.23023 fatcat:beuikbqg55axfbxstgc4icopxe