On the Specificity and Differentiation of Cholinesterases.

Abstract

Conclusions

The ability to hydrolyze noncholine esters can no longer be used as a criterion to distinguish the two cholinesterase types, since both groups of enzymes are able to split noncholine esters; for example, ethyl chloroacetate. Another noncholine ester, β-chloroethyl acetate, is even preferentially attacked by the e-type (“true” or “specific” ChE).

The use of eserine to decide whether a hydrolysis is catalyzed by a cholinesterase or another esterase is of limited value, because the s-type (“pseudo” or “unspecific” ChE) is inhibited by this substance only in the presence of acetylcholine, but not in that of ethyl chloroacetate. The e-type is inhibited in both cases.

Ethyl chloroacetate plus eserine and β-chloroethyl acetate can be used as new means of distinction of the two groups of cholinesterases.