THERMODYNAMIC STUDIES OF THE INTERACTION OF SODIUM N-DODECYL, SULPHATE WITH CALF - THYMUS WISTONE H3

The binding of Sodium n-dodecyl sulphate (SDS) to histone H3 was studied in the pH range 3.2-10 by equilibrium dialysis at 27? and 3 7 ?c .T he binding data have been used to obtain the Gibbs free energy of interaction using a theoretical model of the Wyman binding potential; and the enthalpy of interaction from the temperature dependence of theequilibriumconstantsfronr theVan't Hoff re1ation.The enthalpy of interaction of H3 and SDS is exothermic in some buffer solutions which is in marked contrast to other histone - SDS complexes, The entropy of initial interaction of H3 and SDS is negative in some other buffer solutions with increasing binding of SDS, the entropy becomes positive.