Partial characterization of glutathione S-transferases in pyrethroid-resistant and -susceptible populations of the maize weevil, Sitophilus zeamais
Partial characterization of glutathione S-transferases in pyrethroid-resistant and -susceptible populations of the maize weevil, Sitophilus zeamais
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DOI：
10.1016/j.jspr.2006.04.002
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发表时间：
2007-01-01
影响因子：
2.7
通讯作者：
Oliveira, Maria Goreti A.
中科院分区：
文献类型：
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作者：
Fragoso, Daniel B.;Guedes, Raul Narciso C.;Oliveira, Maria Goreti A.
采用体外比色法对玉米象鼻虫玉米象（Siiophitus Zeamais Motschulsky）的谷胱甘肽s -转移酶（GSTs）进行了测定，并对其敏感种群（Sete Lagoas）和抗性种群（Jacarezinho和Juiz de Fora）进行了鉴定。GSTs在pH为9.0和30℃时表现出较高的活性峰，除来自Juiz de Fora的抗性群体外，GSTs的k值比来自Sete Lagoas的敏感群体在使用其底物（和固定浓度的还原型谷胱甘肽-谷胱甘肽）时高约2倍。以CDNB和GSH为底物时，同一抗性群体的v9也比拟除虫菊酯敏感群体高出2倍以上。在使用这两种底物时，抗性种群的V-max也略高于敏感种群。以DCNB和GSH为底物时，玉米象鼻虫群体GSTs的动力学参数无显著差异。这些结果提供了证据，证明至少在巴西的一些玉米象鼻虫种群中，GST活性的增强参与了额外的拟除虫菊酯抗性机制。(c) 2006 Elsevier Ltd.版权所有。
Glutathione S-transferases (GSTs) from it susceptible (Sete Lagoas) and two pyrethroid-resistant populations (Jacarezinho and Juiz de Fora) of the maize weevil Siiophitus Zeamais Motschulsky (Coleoptera: Curculionidae) were characterized through in vitro colorimetric assays. GSTs showed higher activity peaks at pH 9.0 and 30 degrees C. The K-values for GSTs were similar among the populations except for the resistant population from Juiz de Fora, which was about two-fold higher than the susceptible population from Sete Lagoas when using 1-chloro-2.4-dinitrobenzeiie (CDNB) its substrate (and a fixed concentration of reduced glutathione-GSH). The V 9 of this same resistant population wits also over two-fold higher than that of the pyrethroid-susceptible population when CDNB and GSH were used as substrates. The resistant population from Jacarezinho also had a slightly, but significantly, higher V-max than the susceptible population when using these two substrates. However, there were no significant differences among the kinetic parameters of GSTs from the maize weevil populations when DCNB and GSH were used as substrates. These results provide evidence of the involvement of enhanced GST activity as,in additional pyrethroid-resistant mechanism in at least some maize weevil populations from Brazil. (c) 2006 Elsevier Ltd. All rights reserved.