Denaturation versus pH of lyzozyme and biosynthetic human growth hormone by differential scanning calorimetry and circular dichroism: a comparative study

Abstract The thermal behaviour of lyzozyme and human growth hormone (hGH) in aqueous solutions versus pH was studied by DSC experiments. The temperature and enthalpy of denaturation were determined, showing a maximal stability of lyzozyme at pH 4.5, and a large range of pH (5.0–9.0) corresponding to the maximal stability of hGH. These results are in good agreement with those obtained by circular dichroism measurements. The hGH environment was modified by addition of linear or aromatic small molecules and their influence on the parameters of the denaturation was studied.