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Comparative studies of acetylcholinesterase purified from three field populations of Liposcelis entomophila (enderlein) (psocoptera: liposcelididae)
Author(s) -
Xiao LiSha,
Dou Wei,
Li Yin,
Wang JinJun
Publication year - 2010
Publication title -
archives of insect biochemistry and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.576
H-Index - 66
eISSN - 1520-6327
pISSN - 0739-4462
DOI - 10.1002/arch.20378
Subject(s) - psocoptera , acetylcholinesterase , biology , population , omethoate , biochemistry , aché , pesticide resistance , toxicology , enzyme , pesticide , botany , ecology , demography , sociology
Acetylcholinesterace (AChE) is known to be the major target for organophophate and carbamate insecticides and biomolecular changes to AChE have been demonstrated to be an important mechanism for insecticide resistance in many insect species. In this study, AChE from three field populations of Liposcelis entomophila (Enderlein) (Psocoptera: Liposcelididae) was purified by affinity chromatography and subsequently characterized by its Michaelis‐Menten kinetics to determine if detectable changes to AChE have occurred. Bioassays revealed that the potential resistance threat of psocids in Sichuan Province (GH) was greater than either Hubei Province (WH) or Chongqing Municipality (BB). Compared to the other two populations, the WH population possessed the highest specific activity of purified AChE. Kinetic analyses indicated that the purified AChE from GH population expressed a significantly lower affinity to the substrate and a higher catalytic activity toward acetylthiocholine iodide (ATChI) (i.e., higher K m and V max values) than BB and WH populations. In vitro studies of AChE suggest that five inhibitors (aldicarb, eserine, BW284C51, omethoate, and propoxur) all possess strong inhibitory effects with eserine having the strongest inhibitory effect against purified AChE. According to bimolecular rate constants ( k i ), the purified AChE from GH population was least sensitive to all inhibitors except for omethoate. The differences in AChE among the three populations may be partially attributed to the differences in pesticide application and control practices for psocids among the three locations. © 2010 Wiley Periodicals, Inc.