Thermodynamic aspects of the thermal stability of human serum albumin.

The thermal denaturation of human serum albumin can be described by a two step process according to the model of Eyring and Lumry (N <==> U --> I). It was found that the rate of irreversible process (U-->I) is very slow, allowing its resolution as a reversible one on the basis of two state approximation (N <==> U). The delta H degrees of denaturation was 88.9 degrees Kcal/mol. This suggests that in the unfolding state, the protein partially possesses its tertiary structure. The melting temperature of the protein obtained by differential scanning calorimetry was of 63.14 degrees C, this value was in agreement with those obtained by other techniques such as fluorescence and enzymatic activity of the protein.