Thermodynamics of the isothermal denaturation of lysozyme by guanidinium chloride.

A thermodynamic analysis of the isothermal denaturation of lysozyme by guanidinium chloride has been performed. The analysis is based on the equation which relates the equilibrium constant for denaturation to the preferential binding of denaturant. The equation has been derived previously by thermodynamic methods, whereas in this article a derivation based on statistical mechanics is given. By application of the equation the free energy of denaturation is first calculated and from it, by subtracting the calorimetrically-determined enthalpy of denaturation, the entropy of denaturation is determined.