Partial characterization of glutathione S-transferases from different field populations of <i>Liposcelis bostrychophila</i>

  • W. Dou Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400716, P. R. China
  • J.-Z. Niu Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400716, P. R. China
  • L.-S. Xiao Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400716, P. R. China
  • Y.-X. Deng Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400716, P. R. China
  • J.-J. Wang Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400716, P. R. China, E-mail: jjwang7008@yahoo.com

Abstract

Glutathione S-transferases (GSTs) from different field populations of Liposcelis bostrychophila (Psocoptera: Liposcelididae) were purified by glutathione-agarose affinity chromatography and characterized subsequently by their Michaelis-Menten kinetics toward the artificial substrates 1-chloro- 2,4-dinitrobenzene (CDNB) and reduced glutathione (GSH). The specific activity of the affinity of purified GST toward CDNB was highest in lab population, 2.7-fold higher than that of Guanghan population with the lowest value observed. GSTs of lab population exhibited higher apparent Michaelis-Menten constants (Km) and higher maximal velocity (Vmax) values than those of Jianyang and Guanghan populations, revealing that the latter two populations exhibited significantly higher affinities to the test substrates. Inhibition kinetics showed that all test compounds (ethacrynic acid, curcumin, diethyl maleate, bromosulfalein, and carbosulfan) possessed significant inhibitory effects on GSTs. Curcumin appeared to be the most effective inhibitor. Compared to the other compounds, diethyl maleate and carbosulfan exhibited their I50s (the concentration required to inhibit 50% of GSTs activity) at higher concentrations.

Keywords: GSTs, purification, Psocids, Xenobiotic compounds, Field populations
Veröffentlicht
2010-09-02