title: Insecticide detection through protein engineering of Nippostrongylus brasiliensis acetylcholinesterase B.
abstract: The sensitivity of acetylcholinesterase (AChE) biosensors for insecticide detection could be increased substantially by engineering AChE B of Nippostrongylus brasiliensis. The introduction of 10 single and 4 double mutations into the AChE peptide chain led to an increase in sensitivity to 10 of the 11 insecticides tested. The combination of three mutants with the wild-type enzyme in a multienzyme biosensor array enabled the detection of 11 out of the 14 most important organophosphates and carbamates at concentrations below 10 microg/kg, the maximum residue limit of infant food. The detection limit for pirimiphos methyl could be reduced from 10 microg/L to a value as low as 1 ng/L (3.5 x 10(-)(12) mol/L). The newly created biosensors exhibited an extraordinary high storage stability. There was no loss of sensitivity of N. brasiliensis AChE B, immobilized on screen-printed, disposable electrodes, even after 17-month storage at room temperature.
authors.affiliation: Institute of Technical Biochemistry, University of Stuttgart, Allmandring 31, D-70569 Stuttgart, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Schulze
authors.forename: Susanne B
authors.initials: SB
authors.lastname: Muench
authors.forename: Francois
authors.initials: F
authors.lastname: Villatte
authors.forename: Rolf D
authors.initials: RD
authors.lastname: Schmid
authors.forename: Till T
authors.initials: TT
authors.lastname: Bachmann
mesh_terms: D000110:Acetylcholinesterase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism; D015374:Biosensing Techniques; D002384:Catalysis; D002800:Cholinesterase Inhibitors / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism*; D015870:Gene Expression; D007306:Insecticides / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D009154:Mutation / Q000235:genetics; D009559:Nippostrongylus / Q000201:enzymology* / Q000235:genetics; D010084:Oxidation-Reduction; D015202:Protein Engineering / Q000379:methods*; D017434:Protein Structure, Tertiary; D012680:Sensitivity and Specificity; D013696:Temperature
chemical_list: D001672:Biocompatible Materials; D002800:Cholinesterase Inhibitors; D007306:Insecticides; D000110:Acetylcholinesterase