Thermodynamics of binding of cadmium to bovine serum albumin.
The binding isotherm of Cd2+ ion to bovine serum albumin (BSA) has been investigated by microcalorimetry at 310.15 K and pH 7.0. The thermodynamic parameters of the binding reaction have been determined, and the stoichiometry of the complex is 2:1, indicating that there exist two identical binding sites of BSA with Cd2+ ion. The value of deltarHthetam is -28.4+/-1.7 kJ mol(-1), the free energy of binding deltarGthetam is -25.2 kJ mol(-1), and the entropy of binding deltarSthetam is -10.3 J mol(-1) K(-1). The negative deltarHthetam and deltarSthetam values are observed for the binding reaction of Cd2+ ion and BSA, suggesting that the binding reaction is mainly enthalpy-driven and the entropy is unfavorable for it.
Qu
Song-Sheng
SS
Department of Chemistry, College of Chemistry and Molecular Science, Wuhan University, People's Republic of China.
Liu
Yi
Y
Wang
Tian-Zhi
TZ
Gao
Wen-Ying
WY
D002104:Cadmium / Q000737:chemistry / Q000493:pharmacokinetics*; D002151:Calorimetry; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013816:Thermodynamics
D002104:Cadmium; D012710:Serum Albumin, Bovine