Kinetic constants for the inhibition of camel retinal acetylcholinesterase by the carbamate insecticide lannate

J Biochem Mol Toxicol. 1999;13(1):41-6. doi: 10.1002/(sici)1099-0461(1999)13:1<41::aid-jbt5>3.0.co;2-f.

Abstract

We have designed this study to determine various kinetic parameters of camel retinal membrane-bound acetylcholinesterase (AChE; EC 3.1.1.7) inhibition by carbamate insecticide lannate [methyl N-[[(methylamino)carbonyl]oxy] ethanimidothioate]. All these kinetic constants were derived by simple graphical methods. The value of kinetic parameters was estimated as follows: 0.061 microM)(-1), 1.14 (microM)(-1), 0.216 microM, 0.016 min(-1), 0.0741 (gammaM min)(-1) 0.746 microM, and 4.42 microM for velocity constant (Kv), new inhibition constant (Knic), dissociation constant (Kd), carbamylation rate constant (k2c), overall carbamylation rate constant (k'2), 50% inhibition constant (K150), and 99% inhibition constant (K199), respectively. These unique methods may be used to estimate such kinetic parameters for time-dependent inhibition of enzymes by variety of chemicals, insecticides, herbicides, and drugs.

MeSH terms

  • Acetylcholine / metabolism*
  • Animals
  • Camelus / metabolism*
  • Cholinesterase Inhibitors / pharmacology
  • Insecticides / pharmacology*
  • Kinetics
  • Methomyl / pharmacology*
  • Retina / enzymology*

Substances

  • Cholinesterase Inhibitors
  • Insecticides
  • Methomyl
  • Acetylcholine