微波处理对葡萄糖异构酶性质的影响  

Effect of Microwave Treatment on the Properties of Glucose Isomerase

作　　者：胡国洲[1] 张甫生[1] 胡鹏[1] 陈光静[1] 武菁菁[1] 阚建全[1] 

机构地区：[1]西南大学食品科学学院重庆市农产品加工及贮藏重点实验室农业部农产品贮藏保鲜质量安全风险评估实验室(重庆),重庆400715

出　　处：《食品科学》2014年第3期134-138,共5页Food Science

基　　金：中央高校基本科研业务费专项(XDJK2012B009);重庆市自然科学基金项目(cstc2012jjA80045)

摘　　要：研究微波处理对葡萄糖异构酶酶活性、稳定性、动力学参数及构象的影响。结果表明:不同微波处理时间和微波处理功率对葡萄糖异构酶的活力都有着不同的影响。在70℃处理5 min条件下,当微波功率为300、400 W时,葡萄糖异构酶的相对酶活力分别增加14.23%、8.42%;而当微波功率为600、800 W时,葡萄糖异构酶的相对酶活力分别降低到95.69%、90.78%;微波处理也对葡萄糖异构酶的最适反应温度和动力学参数K m和V max有影响,但对其最适pH值几乎没有影响。紫外和荧光光谱研究表明微波处理将导致葡萄糖异构酶部分去折叠,分子中赖氨酸和色氨酸残基所处的微环境发生变化,葡萄糖异构酶的三级结构因此可能发生了改变,即微波处理可能通过改变葡萄糖异构酶的构象从而改变酶的性质。The effect of microwave treatment on the activity, stability, kinetic parameters and conformation of glucose isomerase（GI） was studied. Results indicated that different periods and power levels of microwave treatment had different effects on GI activity. After microwave treatment at powers of 300 W and 400 W for 5 min at 70 ℃, GI activity was increased by 14.23% and 8.42%, respectively. However, GI retained 95.69% and 90.78% of its original activity at 600 W and 800 W, respectively. The mi crowave treatment also had effects on the optimal reaction temperature and kinetic pa rameters, but had scarce effects on the optimal pH. Moreover, partial unfolding of GI and changes in microenvironment of tryptophan and tyrosine residues were observed from the ultraviolet and fluorescence spectra of microwave-treated GI. Thus we further speculated that the tertiary structure of GI was also disturbed by microwave treatment. As a conclusion, this study demonstrates that microwave treatment can change some properties of GI presumably by changing its conformational structure.

关 键 词：葡萄糖异构酶 微波处理 酶活性 最适反应温度 最适PH值 构象 

分 类 号：Q814.9[生物学—生物工程]