Acetylcholinesterase as polyelectrolyte in reaction with cationic substrates

Abstract

It is shown that the salt effect in acetylcholinesterase-catalyzed hydrolysis of 2-( N-methylmorpholinium) -ethylacetate can be quantitatively described by the equation log( k 2/ K S) = log( k 2/ K S)° — ψlog[M +Z] following from Manning's polyelectrolyte theory; the ψ values for salts with univalent and bivalent cations at different pH values of the reaction medium were in accordance with the conclusions of the theory. Manning's polyelectrolyte theory seems to be a useful framework for studying salt effects in the reactions of charged substrates with enzymes as globular polyions.