Accession Number : ADP008854

Title :   Size of Acyl Group in Choline Esters Determines the Role of Choline Esters in Decarbamoylation of Alkylcarbamoyl-Acetylcholinesterase.

Corporate Author : ARMY MEDICAL RESEARCH INST OF CHEMICAL DEFENSE ABERDEEN PROVING GROUND MD

Personal Author(s) : Sok, Dai-Eun ; Kim, Yun-Bae

Report Date : 13 MAY 1993

Pagination or Media Count : 16

Abstract : The effect of acetylcholine on decarbamoylation of dimethylcarbamoylacetylcholinesterase seems to be composed of activatory and inhibitory properties, which are representatively expressed by pentanoylthiocholine and laurylcholine, respectively. While the activatory effect requires a strict structural requirement, the inhibitory role is exerted by various compounds containing quaternery or tertiary ammonium group. In contrast to acetylcholine ( > 1 mM) showing a similar potency of inhibition in each decarbamoylation, laurylcholine inhibited choline-catalyzed decarbamoylation more selectively than spontaneous or pentanoylthiocholine-induced decarbamoylation, suggesting that the inhibitory action of choline esters my be due to the interaction of choline esters with central binding subsites of the modified enzyme. In further support, it was observed that decarbamoylation of monoethylcarbamoyl-enzyme was more susceptible to the inhibitory action of acetylcholine than that of disethylcarbamoyl-enzyme, whereas laurylcholine inhibited similarly both decarbamoylations. Based on these results, it is proposed that the size of acyl group in choline esters determines not only activatory role but also different types Of inhibitory action of choline esters.

Descriptors :   *CHOLINES, *ESTERS, *ACETYLCHOLINESTERASE, *CHEMICAL RADICALS, *CHOLINESTERASE INHIBITORS, ACETYLCHOLINE, ENZYMES, INHIBITION, INTERACTIONS, POTENCY, REQUIREMENTS, CATALYSIS, RECEPTOR SITES(PHYSIOLOGY).

Subject Categories : Toxicology
      Pharmacology

Distribution Statement : APPROVED FOR PUBLIC RELEASE