Institute of Biochemistry and Biophysics, Tehran University, Tehran, I.R. IRAN
The interaction of histone H2B and dodecyl trimethyl ammonium bromide (DTAB) was studies via equilibrium dialysis method at two different temperatures, at pH 6.4 in phosphate buffer. The binding data were used to obtain the Gibbs free energy of interaction, which is interpreted in terms of a theoretical model based on the Wyman binding potential. The data were then used to obtain the enthalpy of interaction from the temperature dependence of the equilibrium constants by the van't Hoff relation, in order to get a better picture of the thermodynamics of the interaction. The enthalpy of unfolding is found to be consistent with Hill plots which are good estimation of the cooperativity of the system.