高密度二氧化碳对脂肪氧化酶活性与结构变性的影响  

The Effects of Dense Phase Carbon Dioxide on the Activity and Denaturation of Lipoxygenase

作　　者：贝君[1] 吴继红[1] 廖小军[1] 胡小松[1] 

机构地区：[1]中国农业大学食品科学与营养工程学院,北京100083

出　　处：《中国食品学报》2008年第5期51-57,共7页Journal of Chinese Institute Of Food Science and Technology

基　　金：国家"十一五"科技支撑计划课题(2006BAD05A02);国家自然科学基金项目(30571297)

摘　　要：研究了高密度二氧化碳(Dense Phase Carbon Dioxide,DPCD)技术对脂肪氧化酶(Lipoxygenase,LOX)活性与结构变性的影响。采用分光光度法测定LOX的活性,通过测定处理后的巯基含量、浊度等指标考察蛋白质的变性程度;采用电泳方法及透射电镜(Transmission Electric Microscopy,TEM)对处理过的LOX蛋白分子进行形态观察。试验结果显示,DPCD处理对LOX的钝化效果显著高于温和热处理的。55℃处理30min,酶活接近20%,而DPCD(55℃、10MPa)处理30min,酶活不到5%。随着处理温度和压强的增加,LOX活性显著下降,在温度55℃、压强大于10MPa时,LOX已经完全失活。DPCD处理后,LOX液中游离-SH基团的含量和浊度值显著增加,表明DPCD处理使LOX发生了变性。活性电泳和透射电镜观察结果表明,在55℃进行DPCD处理,可能导致LOX蛋白分子的聚合。The effects of DPCD on the activity and denaturation of lipoxygenase（LOX） were investigated. LOX activity was determined by spectrophotometr. Through the determination of hydrosnlfide group content and turbidity after treating, the degree of its protein denaturation was investigated. At the sametime, the form of LOX protein molecule after treating was also observed by electrophoretic method and TEM. Compared with mild heat treatments, DPCD inactivated significantly the LOX. The residual activity of LOX decreased to nearly 20% when exposed to the mild heat treatment at 55 ℃ for 30 min, it was less than 5% at 10 MPa and 55 ℃ for 30 rain. After the DPCD treatment, the buried -SH group was exposed and the turbidity of LOX solution was increased significantly, indicating that DPCD denatured the LOX structure. Moreover, the image of Native-PAGE and TEM showed that DPCD at 55 ℃ possibly led to the aggregation of LOX molecules.

关 键 词：高密度二氧化碳 脂肪氧化酶 酶活 变性 

分 类 号：TS255.1[轻工技术与工程—农产品加工及贮藏工程]