1. Academic Validation
  2. Probing the activity of a non-oxime reactivator for acetylcholinesterase inhibited by organophosphorus nerve agents

Probing the activity of a non-oxime reactivator for acetylcholinesterase inhibited by organophosphorus nerve agents

  • Chem Biol Interact. 2016 Nov 25;259(Pt B):133-141. doi: 10.1016/j.cbi.2016.04.002.
C Linn Cadieux 1 Haoyu Wang 2 Yuchen Zhang 2 Jeffrey A Koenig 3 Tsung-Ming Shih 3 John McDonough 3 John Koh 2 Douglas Cerasoli 3
Affiliations

Affiliations

  • 1 Research Division, United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA. Electronic address: christena.l.cadieux.ctr@mail.mil.
  • 2 Chemistry and Biochemistry Department, University of Delaware, Newark, DE 19716, USA.
  • 3 Research Division, United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA.
Abstract

Currently fielded treatments for nerve agent intoxication include atropine, an acetylcholine receptor antagonist, and pralidoxime (2PAM), a small molecule reactivator of acetylcholinesterase (AChE). 2PAM reactivates nerve agent-inhibited AChE via direct nucleophilic attack by the oxime moiety on the phosphorus center of the bound nerve agent. Due to a permanently charged pyridinium motif, 2PAM is not thought to cross the blood brain barrier and therefore cannot act directly in the neuronal junctions of the brain. In this study, ADOC, a non-permanently charged, non-oxime molecule initially identified using pesticide-inhibited AChE, was characterized in vitro against nerve agent-inhibited recombinant human AChE. The inhibitory and reactivation potentials of ADOC were determined with native AChE and AChE inhibited with tabun, sarin, soman, cyclosarin, VX, or VR and then compared to those of 2PAM. Several structural analogs of ADOC were used to probe the reactivation mechanism of the molecule. Finally, guinea pigs were used to examine the protective efficacy of the compound after exposure to sarin. The results of both in vitro and in vivo testing will be useful in the design of future small molecule reactivators.

Keywords

Acetylcholinesterase; Guinea pig; Organophosphorus nerve agent; Oxime; Pralidoxime; Reactivator.

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