Elucidating the energetics of the interaction of non-toxic dietary pigment curcumin with human serum albumin: A calorimetric study

作者：Basu Anirban; Kumar Gopinatha Suresh^*

来源：Journal of Chemical Thermodynamics, 2014, 70: 176-181.

DOI：10.1016/j.jct.2013.10.037

• Curcumin-HSA interaction
• Thermodynamics
• Enthalpy-entropy compensation

Thermodynamic quantities for the interaction of the anticancer dietary pigment curcumin with human serum albumin were measured by using isothermal titration calorimetry. The equilibrium constant of the complex formation at T = 293.15 K was found to be (5.25 +/- 0.05) 10(5) M-1. The binding was exothermic with T Delta S degrees = (24.82 +/- 0.01) kJ . mol(-1), where Delta S degrees is the standard molar entropy change and Delta H degrees = -(7.28 +/- 0.04) kJ . mol(-1), where Delta H degrees is the standard molar enthalpy change. The stoichiometry of binding was established to be 1:1. The equilibrium constant decreased with increasing Na+ concentration. The equilibrium constant decreased from (5.25 +/- 0.05) . 10(5) M-1 to (2.88 +/- 0.03) . 10(5) M-1 by increasing the salt concentration from (10 to 50) mM. Both polyelectrolytic and non-polyelectrolytic forces contributed to the standard molar Gibbs free energy change. However the contribution from the latter was dominant and almost invariant at all Na+ concentrations. The negative standard molar heat capacity change along with significant enthalpy-entropy compensation suggests the involvement of multiple weak non-covalent forces in the binding process.

• 出版日期2014-3