新型拟除虫菊酯降解酶的分子改造及降解特性  

Molecular modification and degradation characteristics of a novel marine mud-derived pyrethroid hydrolase

作　　者：刘孝龙[1,2] 刘玉焕[2] 范新炯[1,2] 

机构地区：[1]安徽医科大学基础医学院,安徽合肥230032 [2]中山大学生命科学学院,广东广州510275

出　　处：《中山大学学报（自然科学版）》2017年第4期111-117,共7页Acta Scientiarum Naturalium Universitatis Sunyatseni

基　　金：国家自然科学基金(31400680);安徽医科大学博士启动基金(XJ201322);广东省科技计划项目(2012B010300021;2013B010404044);广东省教育项目(2013KJCX0107)

摘　　要：为了获得稳定性和酶活性提高的拟除虫菊酯类降解酶,利用易错PCR技术对来源于海底泥宏基因组文库的新型酯酶基因(est825)进行体外定向进化,获得了一个酶活性和热稳定性均提高的突变酶(Est M46)。与野生型相比其酶活力提高1.5倍;最适反应温度提高了5℃,同时热稳定性明显增强。此外,Est M46对氯氟氰菊酯、氯氰菊酯、氰戊菊酯和溴氰菊酯的降解率分别提升至92.21%、99.75%、93.21%和89.48%。这对降低酶的生产成本、促进工业化发展和环境保护有重要意义。In order to enhance the activity of pyrethroid degrading enzyme, error prone PCR technology was used to modify a novel esterase gene （est825） which was derived from marine sediment metagenomic library. A mutant enzyme EstM46 was cloned and characterized. The activity of EstM46 was 1.5-fold higher than wild type （ Est825 ）, and the optimum temperature was 5 degrees higher than that of Est825. Furthermore, the mutant enzyme stayed stable up to 70 ℃, remaining 80% （50% with Est825 ） of its activity after incubated at 70℃ for 2 h. The hydrolysis rates of cyhalothrin, cypermethrin, sumicidin and deltamethrin were 92.21%, 99.75%, 93.21% and 89.48% , respectively. A broad-spectrum pyre- throid-degrading enzyme with higher hydrolytic activity and more thermostability will play a better role in practical biodegradation.

关 键 词：拟除虫菊酯 农药降解酶 定向进化 生物降解 

分 类 号：Q556.1[生物学—生物化学]