- Catalytic Recruitment by Phosphonyl Derivatives as Inactivators of Acetylcholinesterase and Substrates for Imidazole-Catalyzed Hydrolysis: β-Deuterium Isotope Effects
-
β-Deuterium secondary isotope effects for the phosphonylation of the active site serine of acetylcholinestarase (AChE) by phosphonyl derivatives at 25 deg C and pH 7.70 in 0.05 M phosphate buffer were as follows: 3,3-dimethyl-2-butyl methylphosphonofluoridate (soman), 0.90 +/- 0.03; 2-propyl methylphosphonofluoridate (sarin), 0.91 +/- 0.04; 4-nitrophenyl 2-propyl methylphosphonate (IMN), 0.93 +/- 0.05. β-Deuterium isotope effects for the imidazole-catalyzed hydrolysis of the same three compounds and of bis(4-nitrophenyl) methylphosphonate (NMN) were similar: soman, 0.96 +/- 0.03; sarin, 0.96 +/- 0.02; IMN, 0.96 +/- 0.02 (73.0 +/- 0.01 deg C); NMN, 0.94 +/- 0.02.The results indicate an increase in the force constants for the CL (L = H,D) bonds adjacent to phosphorus at the transition state for phosphonylation.This trend is pronounced in the AChE reaction, conceivably due to a more compressed structure at the transition state for the AChE reaction in comparison to the imidazole-catalyzed hydrolysis of the phosphonyl derivatives.
- Bennet, Andrew J.,Kovach, Ildiko M.,Bibbs, Jeffrey A.
-
-
Read Online
- Synthesis of the Tripeptides Tyr-Thr-Lys Phosphorylated with Isopropyl Methyl- and (Deuteromethyl)phosphonochloridates as Reference Standards for the Analysis of Biomedical Samples
-
A procedure for the phosphorylation of the tripeptide Tyr-Thr-Lys with isopropyl methyl- or (deuteromethyl)phosphonochloridate is developed. The phosphorylated tripeptides are intended for use as reference standards in the analysis of blood samples of people suspected to have been exposed to acetylcholinesterase inhibitors. Conditions of hromatographic separation and purification of the synthesized compounds are determined and optimized, which ensures the preparation of high-purity phosphorylated tripeptides.
- Rodin,Baygildiev,Krylov,Osipov,Krylov,Yashkir,Rybalchenko
-
p. 2103 - 2107
(2019/11/29)
-