title: Heterologous expression of Helicoverpa armigera cytochrome P450 CYP6B7 in Pichia pastoris and interactions of CYP6B7 with insecticides.
abstract: BACKGROUND
  Previous studies indicated that constitutive over-expression of cytochrome P450 CYP6B7 was involved in fenvalerate resistance in Helicoverpa armigera. In this study, the CYP6B7 gene from H. armigera (namely HaCYP6B7), was heterologously expressed in Pichia pastoris GS115. A vector pPICZA-HaCYP6B7 was constructed and transformed into P. pastoris GS115, the transformant of pPICZA-HaCYP6B7-GS115 was then cultured and induced by 1% (v/v) methanol and the heterologous expression of HaCYP6B7 protein in P. pastoris was confirmed by SDS-PAGE and western blot.
  
  
  RESULTS
  Microsomes containing the expressed HaCYP6B7 showed activities against model substrate p-nitroanisole and 7-ethoxycoumarin, with p-nitroanisole O-demethylation (PNOD) and 7-ethoxycoumarin O-deethylation (ECOD) activities of 15.66- and 4.75-fold of the control, respectively. Moreover, it showed degradation activities against the insecticides bifenthrin, fenvalerate and chlorpyrifos, with clearance activities of 6.88-, 1.49- and 2.27-fold of the control, respectively. The interactions of HaCYP6B7 with insecticides were further confirmed by molecular docking in silico with binding scores of 5.450, 5.295 and 2.197 between putative HaCYP6B7 protein and bifenthrin, fenvalerate and chlorpyrifos, respectively.
  
  
  CONCLUSIONS
  The results of present study provided more direct and important evidence on the role of HaCYP6B7 conferring pyrethroid resistance in H. armigera. © 2017 Society of Chemical Industry.
authors.affiliation: College of Science, China Agricultural University, Beijing, China.|College of Plant Protection, Nanjing Agricultural University, Nanjing, China.
authors.forename: Chunqing
authors.identifier: http://orcid.org/0000-0002-7942-488X
authors.initials: C
authors.lastname: Zhao
authors.affiliation: College of Science, China Agricultural University, Beijing, China.
authors.forename: Genmiao
authors.initials: G
authors.lastname: Song
authors.affiliation: College of Science, China Agricultural University, Beijing, China.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Duan
authors.affiliation: College of Science, China Agricultural University, Beijing, China.|Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha, China.
authors.forename: Tao
authors.identifier: http://orcid.org/0000-0002-3128-673X
authors.initials: T
authors.lastname: Tang
authors.affiliation: College of Science, China Agricultural University, Beijing, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
authors.affiliation: College of Science, China Agricultural University, Beijing, China.
authors.forename: Lihong
authors.initials: L
authors.lastname: Qiu
mesh_terms: D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D015870:Gene Expression; D007306:Insecticides / Q000378:metabolism*; D007915:Lepidoptera / Q000201:enzymology* / Q000235:genetics*; D008861:Microsomes / Q000378:metabolism; D062105:Molecular Docking Simulation; D010843:Pichia / Q000235:genetics*; D011485:Protein Binding; D011487:Protein Conformation; D011722:Pyrethrins / Q000378:metabolism*
chemical_list: D007306:Insecticides; D011722:Pyrethrins; D003577:Cytochrome P-450 Enzyme System
keywords: CYP6B7; Helicoverpa armigera; Pichia pastoris; heterologous expression; interaction; molecular docking