污染控制技术及原理
安燕,程江,肖立军,杨卓如,谭蕾.磁场对酪氨酸酶活性及其催化降解酚类有机物影响的研究[J].环境科学学报,2007,27(8):1263-1269
磁场对酪氨酸酶活性及其催化降解酚类有机物影响的研究
- Effect of a magnetic field on the catalytic activity of tyrosinase and its degradation of phenolic compounds
- 基金项目:广东省自然科学基金(No.04020114)
- 安燕
- 1. 华南理工大学化工与能源学院, 广州 510640; 2. 贵州大学化工学院, 贵阳 550003
- 程江
- 华南理工大学化工与能源学院, 广州 510640
- 肖立军
- 华南理工大学化工与能源学院, 广州 510640
- 杨卓如
- 华南理工大学化工与能源学院, 广州 510640
- 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(10~350mT)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3.83mmol·L-1,未磁化的Michaelis常数Km为2.65mmol·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.
- Abstract:The effect of a static magnetic field on tyrosinase(TYR) activity and its degradation of phenolic compounds was studied. TYRactivity 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 60min the activity began to decline. The thermostability and pHstability of magnetized TYRwere also improved, and catalytic activity was promoted between 20~35℃ and pH5.0~10.0. The optimal pHand temperature were 7.0 and 25℃. The Michaelis constant Km of TYRfor catalysis of pyrocatechol was 2.65 mmol·L-1 and that of magnetized TYRwas 3.83 mmol·L-1. The reaction rate of TYRfor catalysis of pyrocatechol, phenol and 2,4-dichlorophenol decreased in sequence, and the magnetic effect of TYRfor catalyzing pyrocatechol was most remarkable among these phenolic compounds. The rates of catalytic degradation of phenol and 2,4-dichlorophenol by magnetized TYRto the removal rate of phenol and 2,4-dichlorophenol 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.
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