产自Bacillus sp.的热稳定偶氮还原酶结构模型研究  

Structure modeling and analysis of thermoactive azoreductase fromBacillus sp.

作　　者：朱超[1] 解井坤[1] 花莉[1] 杨冰[1] 沈烁[2] 

机构地区：[1]陕西科技大学资源与环境学院,陕西西安710021 [2]同济大学环境科学与工程学院,上海200092

出　　处：《陕西科技大学学报（自然科学版）》2014年第6期33-38,60,共7页Journal of Shaanxi University of Science & Technology

基　　金：陕西省教育厅专项科研计划项目(2013JK072);陕西科技大学博士科研启动基金项目(BJ12-29)

摘　　要：位于细菌膜上和胞内的偶氮还原酶可将电子传递给偶氮染料实现其脱色降解,特别是具备热稳定性的偶氮还原酶,在印染废水处理和硝基类芳香化合物污染治理等方面极具应用价值.但是,相关热稳定性偶氮还原酶结构和热稳定性等的研究数据仍然还很有限.Bacillus sp.产偶氮还原酶可在40℃~60℃下依旧保持活性,对其结构和活性关系的深入了解将有助于可应用于极端生产环境的工程化偶氮还原酶的开发.本研究利用同源建模构建了Bacillus thuringiensis的偶氮还原酶STA的三级结构模型,并和其它黄素依赖型偶氮还原酶结构进行了比对.结果显示,STA单体具有类似黄素氧化还原蛋白的α/β型结构的亲水性蛋白质,还具有一个外-内螺旋结构的跨膜区域.同时,通过对一株嗜热芽孢杆菌偶氮还原酶粗提液进行变性和脱色试验验证,并结合结构模型分析,推测出多数Bacillus sp.产偶氮还原酶的热稳定性源于其蛋白质结构中的氢键及疏水相互作用.本研究结果为高温下偶氮还原酶活性的改进提供了理论基础.Azo dyes pose serious threat to public health because of its toxicity and carcinogenicity .Azoreductase locating on membrane and inside bacterial is capable of decolouring and degrading azodyes released by industrial effluents ,especially the ones with thermostability which are promising in the treatment of printing and dying wastewater and the nitro aromatic compound pollution control .But the data available on the structure and thermoactive azoreductase enzyme and its degradation pathway are still very less .We constructed the threedimensional structure model of STA using homology modeling method .Model analysis ,evaluation and the comparisons with the structures of other bacteriaoriented FMN independent azoreductases showed that STA was a hydrophilic proteins with typical α/βstructure and a helix transmembrane zone .The denaturation and decoloration experiments conducted with the raw azoreductase from a thermoactive strain of Bacillus confirms the conclusion draw n in silicon study that the thermostability of this azoreductase depends on its hydrophobic interaction and hydrogen bond .These results will pave way for further increase in azoreductase activity under the high temperature and for better utilization of this dye degradation mechanism .

关 键 词：偶氮还原酶 三级结构 BACILLUS 热稳定性 脱色 

分 类 号：X172[环境科学与工程—环境科学]