Detoxification of insecticides, allechemicals and heavy metals by glutathione S‐transferase SlGSTE1 in the gut of Spodoptera litura
Detoxification of insecticides, allechemicals and heavy metals by glutathione S‐transferase SlGSTE1 in the gut of Spodoptera litura
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DOI：
10.1111/1744-7917.12142
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发表时间：
2015-08
期刊：
影响因子：
4
通讯作者：
Zhibin Xu;X. Zou;Ni Zhang;Q. Feng;Sichun Zheng
中科院分区：
文献类型：
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作者：
Zhibin Xu;X. Zou;Ni Zhang;Q. Feng;Sichun Zheng
昆虫谷胱甘肽S-转移酶（GST）在解毒有毒化合物和消除由这些化合物引起的氧化应激方面发挥重要作用。本研究分析了斜纹夜蛾（Spodoptera litura）谷胱甘肽S转移酶（GST）SlGSTE 1对几种杀虫剂和重金属的解毒活性。毒死蜱和黄毒素显著上调了中肠的SlGSTE 1表达。斜纹。重组SlGSTE 1的Vmax（被底物饱和的酶的反应速率）和Km（米氏常数，等于酶最大反应速率一半时的底物浓度）分别为27.95 ± 0.88 μmol/min/mg和0.87 ± 0.028 mmol/L，1-氯-2，4-二硝基苯的Vmax和Km值分别为22.96 ± 0.78 μmol/min/mg和0.83 ± 0.106 mmol/L。体外间接酶活性测定结果表明，重组SlGSTE 1对毒死蜱、溴氰菊酯、马拉硫磷、辛硫磷和滴滴涕等杀虫剂具有较高的结合活性。与昆虫正常生长所需的铜和锌相比，SlGSTE 1对有毒重金属镉、铬和铅具有更高的结合活性。Western blot分析表明，毒死蜱或镉诱导幼虫肠道中的SlGSTE 1。SlGSTE 1也表现出高的过氧化物酶活性。这些结果表明，SlGSTE 1可能在猪肠道中发挥重要作用。斜纹夜蛾，以保护昆虫免受这些化合物和重金属的毒性影响。
Insect glutathione S‐transferases (GSTs) play important roles in detoxifying toxic compounds and eliminating oxidative stress caused by these compounds. In this study, detoxification activity of the epsilon GST SlGSTE1 in Spodoptera litura was analyzed for several insecticides and heavy metals. SlGSTE1 was significantly up‐regulated by chlorpyrifos and xanthotoxin in the midgut of S. litura. The recombinant SlGSTE1 had Vmax (reaction rate of the enzyme saturated with the substrate) and Km (michaelis constant and equals to the substrate concentration at half of the maximum reaction rate of the enzyme) values of 27.95 ± 0.88 μmol/min/mg and 0.87 ± 0.028 mmol/L for glutathione, respectively, and Vmax and Km values of 22.96 ± 0.78 μmol/min/mg and 0.83 ± 0.106 mmol/L for 1‐chloro‐2,4‐dinitrobenzene, respectively. In vitro enzyme indirect activity assay showed that the recombinant SlGSTE1 possessed high binding activities to the insecticides chlorpyrifos, deltamethrin, malathion, phoxim and dichloro‐diphenyl‐trichloroethane (DDT). SlGSTE1 showed higher binding activity to toxic heavy metals cadmium, chromium and lead than copper and zinc that are required for insect normal growth. Western blot analysis showed that SlGSTE1 was induced in the gut of larvae fed with chlorpyrifos or cadmium. SlGSTE1 also showed high peroxidase activity. All the results together indicate that SlGSTE1 may play an important role in the gut of S. litura to protect the insect from the toxic effects of these compounds and heavy metals.