Are the molten globule and the unfolded states of apo-α-lactalbumin enthalpically equivalent?

Abstract

Recently, the absence of a thermally induced transition has been offered as proof that the unfolded and the molten globule states of apo-α-lactalbumin are enthalpically equivalent. In this paper we demonstrate that that argument is thermodynamically incorrect. In addition, it is shown that the absence of a thermally induced transition at extremely low salt concentrations can be accounted for in terms of the known ionic strength dependence of the transition temperature and the thermodynamic parameters associated with the unfolding of apo-α-lactalbumin.