The Effect of Sugars on the Thermal Denaturation of Lysozyme

Abstract

Abstract Thermal denaturation of lysozyme (hen egg-white) in aqueous sugar solution was studied by DSC measurements at pH 5 and by CD measurements at pH 2.12. All of the sugars investigated show a stabilizing influence on the native conformation. The effect of sugars on the transition temperature of lysozyme almost linearly increased with the increase of the numbers of equatorial hydroxyl groups per molecule of sugars. The ellipticity of the solutions at 294 nm of lysozyme and glucose or arabinose was additive in the value of each component at pH 5. The effect of sugars in stabilizing the protein structure may be due to the intensification of the hydrophobic interactions inside the protein molecule.