Alkylammonium chlorobenzoates are a new group of ester-containing reversible inhibitors of cholinesterases of different animals

Interaction with cholinesterases (ChEs) of nine specially synthesized derivatives of dimethylaminoalkyl esters of 2-chloro-and 2,4-dichlorobenzoic acids and their iodoalkylates is studied. Used as enzyme sources were partially purified preparations of acetylcholinesterase (AChE) from human erythrocytes and butyrylcholinesterase (BChE) from horse blood serum, as well as water homogenates of the frog Rana temporaria brain and of the Pacific squid Todarodes pacificus optical ganglia. The studied benzoates failed to be hydrolyzed by the studied ChEs at the enzyme concentrations exceeding 10 times those used for determination of the acetylthiocholine hydrolysis rate. These compounds have turned out to be reversible inhibitors of ChEs of the mixed-noncompetitive type of action. Effects on the anticholinesterase activity of such structural elements of the inhibitors as the acidic part of the benzoate molecule, length of polymethylene chain in the molecule alcoholic part, and the structure of ammonium group are studied. This study has allowed revealing some peculiarities of the reaction capability of vertebrate and invertebrate ChEs.     

Interaction of reversible inhibitors with the cholinesterase of the squid Berryteuthis magister from different areas of the Bering Sea

Studies have been made of the interaction of 13 onium reversible inhibitors with cholinesterase from the visual ganglia of the squid B. magister from various habitats (Kurile Islands, Olyutorsk-Navarin and Navarin-Alaskan regions). In some of the cases, differences were found between the enzymes from various specimens with respect to values of the generalized inhibitor constant (which is a measure of inhibitor effectiveness) and the pattern of inhibition. These data reveal intraspecific polymorphism in B. magister from the Bering Sea.