Solubilization and Hydrolysis of Ovotransferrin Solubilization of α-chymotrypsin. Enthalpy changes for three processes

Abstract

At 298.15 K, the solubilization of hen ovotransferrin at buffered pH 7.8 (0.08 M Tris⋅HCl buffer, containing 0.1 M CaCl2) and the solubilization of α-chymotrypsin (from bovine pancreas) at non-buffered pH 3.0 (0.001 M HCl) both resulted in large exothermic reactions, being the apparent ΔHs –2485 in the first case and –780.1 kJ mol–1 in the second case, respectively. By contrast, the complete hydrolysis of ovotransferrin (pH 7.8) achieved by using a-chymotrypsin (pH 3.0) gave an endothermic reaction with ΔH=+31.84 kJ mol–1.