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Updated: Jul 3, 2026

Measuring Caenorhabditis elegans Sensitivity to the Acetylcholine Receptor Agonist Levamisole
Published on: June 7, 2022
Hysteresis of insect acetylcholinesterase
A Badiou1, M T Froment, D Fournier
1INRA, Institut National de la Recherche Agronomique, UMR 406 Laboratoire de Toxicologie Environnementale, Avignon, France. badiou@avignon.inra.fr
Abstract:
Pre-steady-state catalytic properties of insect acetylcholinesterase (AChE, EC 3.1.1.7) were studied with the neutral substrate N-methylindoxylacetate. Kinetics of soluble Apis mellifera and Drosophila melanogaster AChE forms showed lags (v(i)=0) before reaching the steady-state. Results were interpreted in terms of slow equilibrium between two conformational states E and E' of insect AChE. Hysteresis of insect AChE has been pointed out for the first time. The hysteretic behaviour was found to depend on the NMIA concentration and the nature of the enzyme. The maximum induction times (tau(max)) to reach the steady-state were 800 and 1000s with soluble AChE from A. mellifera and D.melanogaster, respectively. The orders of magnitude of the tau(max) were high and similar to human AChE and BuChE.
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