Abstract
The inhibition kinetics for some organophosphates (paraoxon, DFP, sarin, VX [ethyl S-diisopropylaminoethyl methylthiophosphonate], soman and soman isomers) and carbamates (physostigmine, neostigmine, pyridostigmine and carbaryl) in the reaction with acetylcholinesterase from electric eel were studied. Kd and rate constants for the irreversible step were determined. The great differences in inhibitory power of the organophosphates were mostly due to differences in affinity. A possible correlation between affinity and bonding rate was discussed.