title: Heterologous expression and characterization of a sigma glutathione S-transferase involved in carbaryl detoxification from oriental migratory locust, Locusta migratoria manilensis (Meyen).
abstract: Glutathione S-transferases (GSTs) play a major role in detoxification of xenobiotics and resistance to insecticides in insects. In the present study, a sigma-class GST gene (LmGSTs3) was identified from the locust, Locusta migratoria manilensis. Its full-length cDNA sequence is 828 bp containing an open reading frame (ORF) of 612 bp that encodes 204 amino acid residues. The predicted protein molecular mass and pI are 23.4 kDa and 7.62, respectively. Recombinant LmGSTs3 was heterologously expressed in Escherichia coli as a soluble fusion protein. Its optimal activity was observed at pH 8.0. Incubation for 30 min at temperatures below 40 °C scarcely affected activity. The LmGSTs3 at pH values between 4.0 and 11.0 retained more than 80% of its original activity. Ethacrynic acid and cibacron blue were very effective inhibitors of LmGSTs3 with I50-values 1.7 and 3.7 μM, respectively. In response to heavy metal (CuSO4, CdCl2) exposure there was a concentration-dependent and time-dependent decrease in activity. The nymph mortalities after carbaryl treatment increased 38.7% after LmGSTs3 were silenced. These results suggest that LmGSTs3 may be involved in carbaryl detoxification in L. migratoria manilensis.
authors.affiliation: Research Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi 030006, China.
authors.forename: Guohua
authors.initials: G
authors.lastname: Qin
authors.forename: Miao
authors.initials: M
authors.lastname: Jia
authors.forename: Ting
authors.initials: T
authors.lastname: Liu
authors.forename: Xueyao
authors.initials: X
authors.lastname: Zhang
authors.forename: Yaping
authors.initials: Y
authors.lastname: Guo
authors.forename: Kun Yan
authors.initials: KY
authors.lastname: Zhu
authors.forename: Enbo
authors.initials: E
authors.lastname: Ma
authors.forename: Jianzhen
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D012721:Carbaryl / Q000378:metabolism*; D005982:Glutathione Transferase / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008658:Inactivation, Metabolic; D019476:Insect Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D007305:Insecticide Resistance; D007306:Insecticides / Q000378:metabolism*; D048188:Locusta migratoria / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D034622:RNA Interference; D011994:Recombinant Proteins / Q000378:metabolism; D017422:Sequence Analysis, DNA
chemical_list: D019476:Insect Proteins; D007306:Insecticides; D011994:Recombinant Proteins; D005982:Glutathione Transferase; D012721:Carbaryl