A thermodynamic study on the interaction of Jack bean urease, JBU, with Zn2＋ and Cd2＋ ions was studied by isothermal titration calorimetry （ITC） at 290, 300 and 310 K in 30 mmol/L Tris buffer solution, pH 7.0. The...A thermodynamic study on the interaction of Jack bean urease, JBU, with Zn2＋ and Cd2＋ ions was studied by isothermal titration calorimetry （ITC） at 290, 300 and 310 K in 30 mmol/L Tris buffer solution, pH 7.0. The heats of JBU＋Zn2＋ and JBU＋Cd2＋ interactions are reported and analyzed in terms of the extended solvation theory. It was indicated that there is a set of 12 identical and non-interacting binding sites for Zn2＋ and Cd2＋ ions. The interactions of Zn2＋ and Cd2＋ ions with JBU are exothermic and both enthalpy and entropy driven. The association equilibrium constants for JBU＋Zn2＋ complexes are 4118.20, 3354.70 and 2790.62 Lomol 1 at 290, 300 and 310 K respectively. The association equilibrium constants for JBU＋Cd2＋ interactions are 2831.6 and 2386.28 Lomol 1 at 300 and 310 K, respectively.展开更多
文摘A thermodynamic study on the interaction of Jack bean urease, JBU, with Zn2＋ and Cd2＋ ions was studied by isothermal titration calorimetry （ITC） at 290, 300 and 310 K in 30 mmol/L Tris buffer solution, pH 7.0. The heats of JBU＋Zn2＋ and JBU＋Cd2＋ interactions are reported and analyzed in terms of the extended solvation theory. It was indicated that there is a set of 12 identical and non-interacting binding sites for Zn2＋ and Cd2＋ ions. The interactions of Zn2＋ and Cd2＋ ions with JBU are exothermic and both enthalpy and entropy driven. The association equilibrium constants for JBU＋Zn2＋ complexes are 4118.20, 3354.70 and 2790.62 Lomol 1 at 290, 300 and 310 K respectively. The association equilibrium constants for JBU＋Cd2＋ interactions are 2831.6 and 2386.28 Lomol 1 at 300 and 310 K, respectively.
