作　　者： ; ; ; ; ;

机构地区： 华南理工大学化学与化工学院

出　　处： 《环境科学学报》 2007年第8期1263-1269,共7页

摘　　要： 研究了恒磁场对酪氨酸酶（TYR）活性及其催化降解酚类有机物的影响.结果显示,不同磁场强度（10～350 mT）处理下TYR酶活性均有提高,最佳磁场强度150mT下酶活力提高了27.1%.不同磁化时间下TYR酶活都有上升,但磁化60min后酶活上升幅度有所下降.酶经磁场处理后对温度、pH值稳定性增强,在温度为20～35 ℃、pH为5.0～10.0时均能保持较高活性,最佳温度为25℃,最佳pH为7.0;磁化后TYR酶的Michaelis常数Km为3.83 mmol·L^-1,未磁化的Michaelis常数Km为2.65 mmol·L^-1.磁场作用可促进TYR对酚类有机物邻苯二酚、苯酚、2,4-二氯酚的转化,反应速度依次递减,磁化处理对邻苯二酚反应的促进作用尤其明显;磁化处理后的酶对不同浓度苯酚和2,4-二氯酚的去除率均明显高于未磁化处理的酶,且随着酶用量增加,酚去除率提高.荧光发射光谱分析表明,磁化酪氨酸酶的荧光强度增强,构像发生了变化. The effect of a static magnetic field on tyrosinase（TYR） activity and its degradation of phenolic compounds was studied. TYR activity was enhanced at a magnetic intensity range of 10 - 350mT, and an enhancement factor of 27. 1% was found at the optimal magnetic field of 150mT. The activity increased with magnetization time, but after 60rain the activity began to decline. The thermostability and pH stability of magnetized TYR were also improved, and catalytic activity was promoted between 20 - 35℃ and pH 5.0 - 10.0. The optimal pH and temperature were 7.0 and 25~C. The Miehaelis constant gm of TYR for catalysis of pyrocateehol was 2.65 mmol· L^-1 and that of magnetized TYR was 3.83 mmol· L^-1 . The reaction rate of TYR for catalysis of pyroeateehol, phenol and 2,4-diehlorophenol decreased in sequence, and the magnetic effect of TYR for catalyzing pyroeateehol was most remarkable among these phenolic compounds. The rates of catalytic degradation of phenol and 2,4-diehlorophenol by magnetized TYR to the removal rate of phenol and 2,4-diehlorophenol on different concentrations were obviously higher than those of TYR, and the removal rate of phenolic compounds was increased with amount of enzyme added. The fluorescence spectrum indicated that the fluorescence intensity of magnetized TYR was enhanced, and its conformation was changed.

关 键 词： 磁场 酪氨酸酶 酚 催化活性 构像

领　　域： [环境科学与工程]