Research Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi Province, China.
PLoS One. 2013;8(3):e58410. doi: 10.1371/journal.pone.0058410. Epub 2013 Mar 7.
Glutathione S-transferases (GSTs) play an important role in detoxification of xenobiotics in both prokaryotic and eukaryotic cells. In this study, four GSTs (LmGSTd1, LmGSTs5, LmGSTt1, and LmGSTu1) representing different classes were identified from the migratory locust, Locusta migratoria. These four proteins were heterologously expressed in Escherichia coli as soluble fusion proteins, purified by Ni(2+)-nitrilotriacetic acid agarose column and biochemically characterized. LmGSTd1, LmGSTs5, and LmGSTu1 showed high activities with 1-chloro-2, 4-dinitrobenzene (CDNB), detectable activity with p-nitro-benzyl chloride (p-NBC) and 1, 2-dichloro-4-nitrobenzene (DCNB), whereas LmGSTt1 showed high activity with p-NBC and detectable activity with CDNB. The optimal pH of the locust GSTs ranged between 7.0 to 9.0. Ethacrynic acid and reactive blue effectively inhibited all four GSTs. LmGSTs5 was most sensitive to heavy metals (Cu(2+) and Cd(2+)). The maximum expression of the four GSTs was observed in Malpighian tubules and fat bodies as evaluated by western blot. The nymph mortalities after carbaryl treatment increased by 28 and 12% after LmGSTs5 and LmGSTu1 were silenced, respectively. The nymph mortalities after malathion and chlorpyrifos treatments increased by 26 and 18% after LmGSTs5 and LmGSTu1 were silenced, respectively. These results suggest that sigma GSTs in L. migratoria play a significant role in carbaryl detoxification, whereas some of other GSTs may also involve in the detoxification of carbaryl and chlorpyrifos.
谷胱甘肽 S-转移酶（GSTs）在原核和真核细胞中外源物的解毒中起着重要作用。本研究从飞蝗中鉴定了 4 种 GSTs（LmGSTd1、LmGSTs5、LmGSTt1 和 LmGSTu1），它们代表不同的类别。这四种蛋白均作为可溶性融合蛋白在大肠杆菌中异源表达，通过 Ni（2+）-次氮基三乙酸琼脂糖柱纯化，并进行了生化特性分析。LmGSTd1、LmGSTs5 和 LmGSTu1 对 1-氯-2,4-二硝基苯（CDNB）表现出高活性，对对硝基苄氯（p-NBC）和 1,2-二氯-4-硝基苯（DCNB）表现出可检测的活性，而 LmGSTt1 对 p-NBC 表现出高活性，对 CDNB 表现出可检测的活性。飞蝗 GSTs 的最适 pH 值在 7.0 到 9.0 之间。依他尼酸和活性蓝可有效抑制这 4 种 GSTs。LmGSTs5 对重金属（Cu（2+）和 Cd（2+））最为敏感。Western blot 分析表明，在马氏管和脂肪体中，这 4 种 GSTs 的表达量最大。LmGSTs5 和 LmGSTu1 沉默后，氨基甲酸酯类杀虫剂西维因处理的若虫死亡率分别增加了 28%和 12%。LmGSTs5 和 LmGSTu1 沉默后，有机磷杀虫剂马拉硫磷和毒死蜱处理的若虫死亡率分别增加了 26%和 18%。这些结果表明，飞蝗 sigma GSTs 在西维因解毒中起着重要作用，而其他一些 GSTs 可能也参与了西维因和毒死蜱的解毒过程。
