Identification and characterization of a novel carboxylesterase from Phaseolus vulgaris for detection of organophosphate and carbamates pesticides

Abstract BACKGROUND Organophosphate and carbamate pesticide residues in food and the environment pose a great threat to human health and have made the easy and rapid detection of these pesticide residues an important task. Discovering new enzyme sources from plants can help reduce the cost of large‐scale applications of rapid pesticide detection via enzyme inhibition. RESULTS Plant esterase from kidney beans was purified. Kidney bean esterase is identified as a carboxylesterase by substrate and inhibitor specificity tests and mass spectrometry identification. The kidney bean esterase demonstrates optimal catalytic activity at 40 °C, pH 6.5 and an enzyme concentration of 0.30 µg mL−1. The kidney bean esterase can be inhibited by organophosphate and carbamate pesticides, which can be substituted for acetylcholinesterase. The limit of detection of the purified kidney bean esterase was two‐ to 20‐fold higher than that of the crude one. The method detection limit meets the detection requirement for the maximum residue limits (MRL) in actual samples. CONCLUSION The findings of the present study provide a new source of enzymes for pesticides detection by enzyme inhibition. © 2018 Society of Chemical Industry