* To whom correspondence should be addressed.
Received November 13, 1998; Revision received December 7, 1998
The model for thermal denaturation of proteins involving consecutive reversible and irreversible steps (Lumry and Eyring model) has been analyzed. The most general case, when equilibrium in the first step is established slowly in comparison with the rate of the second step and the heat effect value for the second step is either greater than or less than zero, has been considered. The theoretical dependences of excess heat capacity on temperature have been constructed. The variation of the shape of the theoretical curves with varied values of the enthalpy change for the second step, Arrhenius equation parameters for both steps, and the scanning rate has been studied.
KEY WORDS: protein denaturation, Lumry and Eyring model, Arrhenius equation, differential scanning calorimetry