A new simple method for determining the kinetic constants of inhibited acetylcholinesterase.

: The authors, with a spectrophotometric procedure, have evaluated the kinetic constants of physostigmine, a cholinesterase inhibitor which assumes an important function when the degeneration of cholinergic projections is observed. This approach overcomes some of the difficulties encountered in measuring the binding and the carbamylation rate constants. A kinetic treatment, consistent with the experimental results observed in the enzyme-inhibitor system in the presence of substrate, is developed.