How the cholinesterases got their modern names.

The classification of the cholinesterases into 'true' and 'pseudo' became obsolete when, some 60 years ago, the author and his co-workers showed that both enzymes had a broad specificity and differed mainly in their acyl group specificity. The importance of complementarity between enzyme and substrate was shown by the high rate of hydrolysis of carbon analogues of choline esters and this enabled pioneer studies of the intermolecular forces between the enzymes' active centres and their substrates to be carried out.