Effect of Hydration on the Thermal Denaturation of Lysozyme as Measured by Differential Scanning Calorimetry

The thermal properties of the lysozyme-water system were investigated by differential scanning calorimetry under varied water contents, ranging from 0.05 to 1.6 g per g of protein. The temperature, Td, and the enthalpy change, ΔHd of denaturation at water contents below 0.75 g/g showed strong dependencies on the hydration. At higher water contents, however, Td and ΔHd were almost independent of the degree of hydration, showing values almost identical to those in solution.