Thermodynamic studies of myelin basic protein upon interaction with zinc

The interaction of myelin basic protein (MBP) from bovine central nervous s ystem with divalent zinc ion was studied by UV-Vis titration spectrophotome try and isothermal titration calorimetry techniques at 27 degreesC in Tris buffer solution at pH = 7.2. MBP has one binding site for a zinc ion. The b inding of a zinc ion is endothermic (DeltaH = +159 kJ mol(-1)) with a disso ciation binding constant of 0.445 muM. The results obtained by two previous methods of isothermal titration spectrophotometry and calorimetry are simi lar and consistent with the result obtained from a new calculation method o f calorimetric data analysis according to the Scatchard plot.