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A simple glutathione transferase-based colorimetric endpoint assay for insecticide detection

Dowd, Andrew, Steven, Andrew, Morou, Evangelia, Hemingway, Janet ORCID:, Vontas, John and Paine, Mark ORCID: (2009) 'A simple glutathione transferase-based colorimetric endpoint assay for insecticide detection'. Enzyme and Microbial Technology, Vol 45, Issue 2, pp. 164-168.

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The natural ability of the detoxification enzymes glutathione transferases (GSTs) to interact with xenobiotics can be used for the production of colorimetric assays. Detection is usually based on the inhibition of the GST-catalysed reaction, with detection achieved spectrophotometrically or electrochemically. Here we have adopted a chromogenic (visual) activity assay for screening GSTs with alkyltransferase activity for iodoalkene substrates for detection of insecticides. We screened a number of GSTs from insecticide resistant mosquito species for their ability to catalyse iodoalkane biotransformation reactions. AaGSTE2 was found to metabolise iodoethane with high turnover, which resulted in a dark blue colour in the enzymatic reaction. Following assay optimisation we exploited the high recognition affinity of the AgGSTE2 for insecticides to develop a novel colorimetric detection assay for organochlorine and pyrethroid quantification. Calibration curves were obtained for permethim, deltamethrin. lambda-cyhalothrin and DDT, with useful concentration ranges of 0-40 mu g/ml (0-100 mu M), 0-50 mu g/ml (0-100 mu M), 0-100 mu g/ml (0-220 mu M), and 0-50 mu g/ml (0-140 mu M), respectively. The assay was validated with extracts from insecticide sprayed surfaces and found to be reproducible and reliable compared with HPLC. The assay is therefore suitable for monitoring insecticide residues in insecticide treated materials, and therefore has potential for insect vector control operations. (C) 2009 Elsevier Inc. All rights reserved.

Item Type: Article
Uncontrolled Keywords: GST Malaria Insecticide Mosquito Vector control
Subjects: QX Parasitology > QX 20 Research (General)
WC Communicable Diseases > Tropical and Parasitic Diseases > WC 750 Malaria
QX Parasitology > Insects. Other Parasites > QX 510 Mosquitoes
QV Pharmacology > Toxicology > General Toxicology > QV 602 Detection of poisons. Tests. Laboratory manuals. Technique
QX Parasitology > Insects. Other Parasites > QX 650 Insect vectors
QX Parasitology > Insects. Other Parasites > QX 600 Insect control. Tick control
Faculty: Department: Groups (2002 - 2012) > Vector Group
Digital Object Identifer (DOI):
Depositing User: Users 183 not found.
Date Deposited: 15 Jun 2010 13:57
Last Modified: 06 Feb 2018 12:59


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