Calorimetric study of the effect of intrachain cross-linking on lysozyme unfolding.
Thermodynamics of unfolding of lysozyme cross-linked between Glu 35 and Trp 108 were studied in solutions of various concentrations of 1-propanol (1-PrOH) at pH 3.7 by means of scanning microcalorimetry. The transition temperature for the cross-linked lysozyme increases by 17-19 degrees C due to cross-linking at every concentration of 1-PrOH. This corresponds to the increase in the unfolding Gibbs free energy of about 28 kJ.mol-1, which is independent of the concentration of 1-PrOH. It was found that the unfolding enthalpy of cross-linked lysozyme is only slightly larger than that of intact one, and the unfolding entropy of the cross-linked one is nearly equal to that of the intact one, if both are compared at the same temperature. The stabilization mechanism for the cross-linked lysozyme is discussed on the basis of these calorimetric data.
Segawa
S
S
Sugihara
M
M
Maeda
T
T
Mitsuhisa
Y
Y
Kodama
M
M
Seki
S
S
Sakiyama
M
M
D000433:1-Propanol / Q000494:pharmacology*; D002152:Calorimetry, Differential Scanning; D003432:Cross-Linking Reagents; D007700:Kinetics; D009113:Muramidase / Q000378:metabolism*; D011487:Protein Conformation; D011489:Protein Denaturation
D003432:Cross-Linking Reagents; D000433:1-Propanol; D009113:Muramidase