Abstract
The kinetics of inhibition of horse serum cholinesterase (EC 3.1.1.8) by six trialkylphosphorothiolates was studied (25° C, pH 7.4). The compounds were: OOS-trimethylphosphorothiolate (OOS-Me), OSS-trimethylphosphorodithiolate (OSS-Me), SSS-trimethylphosphorotrithiolate (SSS-Me) and their corresponding ethyl analogues (OOS-Et, OSS-Et, SSS-Et). The second order rate constants of inhibition ranged from 7.2 to 2128 mol−1 1 min−1, and the enzyme/inhibitor dissociation constants from 0.079 to 1.5 mM. The ethyl esters were better inhibitors than their methyl analogues and the OSS-compounds were better inhibitors than the OOS-or SSS-compounds. The same structure-activity relationship is known to hold for the reaction of the compounds with acetylcholinesterase (EC 3.1.1.7).
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This work is taken in part from the BSc Thesis of L. F. (University of Zagreb)
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Franciskovic, L., Radic, Z. & Reiner, E. Inhibition of serum cholinesterase by trialkylphosphorothiolates. Arch Toxicol 63, 489–491 (1989). https://doi.org/10.1007/BF00316454
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DOI: https://doi.org/10.1007/BF00316454