Thermodynamics of alpha-lactalbumin unfolding.

Thermodynamic investigations of alpha-lactalbumin have been performed by isothermal calorimetric guanidine hydrochloride titrations as well as by scanning calorimetric measurements in the presence and absence of guanidine hydrochloride. Compared with lysozyme, alpha-lactalbumin is less stable, and its changes of enthalpy and heat capacity at unfolding are lower. Thermal unfolding of alpha lactalbumin can be described to the first approximation by the two-state transition model even in the presence of guanidine hydrochloride.