Abstract: Creatine kinase(CK) is a good model for studying protein folding and stability.The result of thermal inactivation showed that trehalose could prevent the thermal inactivation and thermal denaturation of human brain-type creatine kinase(hBBCK).In the presence of 1.0 mol/L trehalose, the midpoint temperature of thermal inactivation(T_m) of hBBCK increased by 4.6℃, and the activation energy(E_a) for thermal inactivation increased from 29.7 to 41.1 kJ/mol.Intrinsic fluorescence spectra also showed an increase in the apparent transition temperature(T_1/2) of hBBCK from 43.0 to 46.5, 47.7 and 49.9℃ in 0, 0.6, 0.8 and 1.2 mol/L trehalose, respectively.The results of intrinsic fluorescence spectra and extrinsic fluorescence spectra of ANS showed that the hydrophobic effects of trehalose might play an important role in thermal stability of hBBCK.The result of renaturation kinetics experiment showed that trehalose could effectively block the coagulation of hBBCK during renaturation process.

Key words: human brain-type creatine kinase(hBBCK); trehalose; thermal denaturation