Thermodynamic Study of Myelin Basic Protein upon Interaction with [Hg2+] Using Extension Solvation Model

Mercury ion interaction with myelin basic protein (MBP) was studied at 300 K in 30 mmol/L tris buffer, pH=7 by isothermal titration calorimetry (ITC). An extended solvation model was used for Hg2++MBP interaction over the whole range of Hg2+ concentrations. The binding parameters recovered from the solvation model were attributed to the structural changes of MBP due to its interaction with mercury ion. It was found that mercury ion acted as a noncooperative effector of MBP, and there is a set of two identical and independent binding sites for Hg2+ ions. The dissociation equilibrium constant is 97.6 µmol/L. The molar enthalpy change of binding is −11.25 kJ·mol−1. Mercury ion interaction with myelin basic protein (MBP) was studied at 300 K in 30 mmol/L tris buffer, pH=7 by isothermal titration calorimetry (ITC). An extended solvation model was used for Hg2++MBP interaction over the whole range of Hg2+ concentrations. The binding parameters recovered from the solvation model were attributed to the structural changes of MBP due to its interaction with mercury ion.