In a previous paper, we report a preliminary DSC study on bovine (BSA) and human (HSA) serum albumins. However, at accurate
HPLC analysis the commercial proteins show three peaks: Fraction V-I, probably globulins (as declared by the producers), Fraction
V-II (about 15–18% of the product) and Fraction V-III that represents pure BSA or HSA. A hypothesis is that the Fraction II
is a covalent dimer, or trimer or a mixture of both, generated during the scalf-life of the commercial product.
Denaturation enthalpies of the purified Fraction V-III and Fraction V-II of BSA, have been determined calorimetrically, at
changing thepH, and the results of both compared with those obtained on the untreated protein. Few calorimetric experiments have been also
carried on a BSA monomer derivative with sulphidril group protected. Computer program have been developed for the deconvolution
of exo- and endothermic effects and for the analysis of thermal denaturation profiles.