Small molecular products of dealkylation in soman-inhibited electric eel acetylcholinesterase.
Product analysis of dealkylation in P(S)C(S)-soman-inhibited electric eel acetylcholinesterase (AChE) by GC-MS using the selected ion monitoring mode has been carried out. The instrument was calibrated with pure standards of 2,3-dimethyl-1-butene and 2, 3-dimethyl-2-butene in the gas phase and methylene chloride extracts of 2,3-dimethyl-2-butanol and 3,3-dimethyl-2-butanol from the aqueous phase. The dealkylation in soman-inhibited AChE at pH 5.0 +/- 0.2 and 25 degrees C produces close to 40% alkenes and 50-60% 2, 3-dimethyl-2-butanol. No 3,3-dimethyl-2-butanol could be detected to provide direct evidence of the intervention of a secondary carbenium ion in the reaction path. All the products of the reaction originate from a tertiary carbenium ion. These findings are in good agreement with the results of Michel et al. [(1967) Arch. Biochem. Biophys. 121, 29], which were obtained by countercurrent distribution of tritium-labeled products and their identification by scintillation counting. The early experiments were performed with the mixture of the four soman diastereomers, all labeled with tritium in Calpha.
Viragh
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Department of Chemistry, The Catholic University of America, Washington, D.C. 20064, USA.
Kovach
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Pannell
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D000110:Acetylcholinesterase / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D002800:Cholinesterase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D002849:Chromatography, Gas; D003640:Dealkylation; D004593:Electrophorus; D006586:Hexanes / Q000737:chemistry; D000441:Hexanols / Q000737:chemistry; D013058:Mass Spectrometry; D012999:Soman / Q000494:pharmacology*
D002800:Cholinesterase Inhibitors; D006586:Hexanes; D000441:Hexanols; C036260:1-hexanol; D012999:Soman; D000110:Acetylcholinesterase