Size of Acyl Group in Choline Esters Determines the Role of Choline Esters in Decarbamoylation of Alkylcarbamoyl-Acetylcholinesterase.
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.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 13, 1993
- Accession Number
- ADP008854
Entities
People
- Dai-eun Sok
- Yun-bae Kim
Organizations
- United States Army Medical Research Institute of Chemical Defense