关键词: 漆酶, 层层自组装, 固定化, 热稳定性, 存储稳定性

Abstract:

Laccase was immobilized through the electrostatic layer-by-layer self-assembly,and cationic polyacrylamide ( CPAM) /laccase self-assembled films were prepared on solid substrate ( mica) . Then,the activities and morphologies of the films were characterized by means of the UV-Vis spectroscopy and the atomic force microscopy,and the enzymatic properties of the immobilized laccase were also analyzed. The results show that the activity of the
CPAM /laccase self-assembled film linearly increases with the number of layers,and the enzyme loading can be effectively controlled by changing the adsorption cycles,and that the laccase molecules are arranged orderly in the films,and the average height and RMS roughness of the self-assembled film increase with the number of layers.Moreover,it is found that the optimal pH value and temperature of the immobilized laccase are respectively 5. 0 and 50℃,which is 5 ℃ higher than that of free laccase,and the corresponding Michaelis constant for ABTS is 0. 042mmol /L,that the thermal stabilities of the immobilized laccase is significantly higher than those of free laccase,and that the immobilized laccase is of excellent reusability and high storage stability.

Key words: laccase, layer-by-layer self-assembly, immobilization, thermal stability, storage stability