Kinetics for the inhibition of acetylcholinesterase from the electric eel by some organophosphates and carbamates.

The inhibition kinetics for some organophosphates (paroxon, diisopropylfluorophosphate, sarin, VX, soman and soman isomers) and carbamates (physostigmine, neostigmine, pyridostigmine and carbaryl) in the reaction with acetylcholinesterase from electric eel have been studied. Dissociation constants and rate constants for the irreversible step were determined. The great differences in inhibitory power of the organophosphates were almost entirely due to differences in affinity. A possible correlation between affinity and bonding rate is discussed.