Stability parameters for β-lactoglobulin thermal dissociation and unfolding in phosphate buffer at pH 7.0

The thermal stability of β-lactoglobulin (β-Lg) dimer was reassessed based on a three-state denaturation process involving dissociation and unfolding (dimer⇌monomer⇌unfolded state). The stabilisation Gibbs free energy change for β-Lg dissociation unfolding (ΔGDCUO) was 57.6 kJ mol−1 compared with an estimated 14 kJ mol−1 with β-Lg monomer as the reference native state. The standard enthalpy (ΔHO) and entropy (Delta;SO) change for heat denaturing β-Lg dimer are reported. The new stability parameters are discussed in terms of protein stability function relations.