Author/Authors :
TAZIKEH، E نويسنده Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, I. R. of Iran TAZIKEH, E , SABOURY، A. A نويسنده Institute of Biochemistry and Biophysics, University of Tehran, Tehran, I. R. of Iran SABOURY, A. A , REZAEI-BEHBEHANI، G نويسنده 3Department of Chemistry, Imam Khomeini International University, Qazvin, I. R. of Iran REZAEI-BEHBEHANI, G , MOOSAVI-MOVAHEDI، A. A نويسنده Institute of Biochemistry and Biophysics, University of Tehran, Tehran, I. R. of Iran MOOSAVI-MOVAHEDI, A. A , MONAJJEMI، M نويسنده Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, I. R. of Iran MONAJJEMI, M
Abstract :
A thermodynamic study on the interaction between zinc ion (Zn2+) and human growth hormone
(hGH) was studied at two temperatures of 27?C and 37?C in aqueous solution using an isothermal titration
calorimetry. It was found that there is a set of three identical and non-interacting binding sites for Zn2+ ions.
The intrinsic dissociation equilibrium constant and the molar enthalpy of binding are 1.54 mM and ?17.6 kJ
mol-1 at 27?C and 1.93 mM and ??7.1 kJ mol-1 at 37?C, respectively. To reproduce the binding parameters of
metal ion?hormone interaction over the whole range of Zn2+ concentrations a solvation theory was applied.
The binding parameters deduced from the solvation model were attributed to the structural change of hGH
and its biological activity due to the metal ion interaction.
