Plant-derived human acetylcholinesterase-R provides protection from lethal organophosphate poisoning and its chronic aftermath

Tama Evron, Brian C. Geyer, Irene Cherni, Mrinalini Muralidharan, Jacquelyn Kilbourne, Samuel P. Fletcher, Hermona Soreq, Tsafrir Leket-Mor

Research output: Contribution to journalArticle

32 Scopus citations

Abstract

Therapeutically valuable proteins are often rare and/or unstable in their natural context, calling for production solutions in heterologous systems. A relevant example is that of the stress-induced, normally rare, and naturally unstable "read-through" human acetylcholinesterase variant, AChE-R. AChE-R shares its active site with the synaptic AChE-S variant, which is the target of poisonous organophosphate anticholinesterase insecticides such as the parathion metabolite paraoxon. Inherent AChE-R overproduction under organophosphate intoxication confers both short-term protection (as a bioscavenger) and long-term neuromuscular damages (as a regulator). Here we report the purification, characterization, and testing of human, endoplasmic reticulumretained AChE-RER produced from plant-optimized cDNA in Nicotiana benthamiana plants. AChE-RER purified to homogeneity showed indistinguishable biochemical properties, with IC50 = 10 -7 M for the organophosphate paraoxon, similar to mammalian cell culture-derived AChE. In vivo titration showed dose-dependent protection by intravenously injected AChE-RER of FVB/N male mice challenged with a lethal dose of paraoxon, with complete elimination of short-term clinical symptoms at near molar equivalence. By 10 days postexposure, AChE-R prophylaxis markedly limited postexposure increases in plasma murine AChE-R levels while minimizing the organophosphate-induced neuromuscular junction dismorphology. Our findings present plant-produced AChE-RER as a bimodal agent, conferring both short- and long-term protection from organophosphate intoxication.

Original languageEnglish (US)
Pages (from-to)2961-2969
Number of pages9
JournalFASEB Journal
Volume21
Issue number11
DOIs
StatePublished - Sep 1 2007

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Keywords

  • Bioscavenger
  • Long-term protection
  • Neuromuscular junction
  • Paraoxon intoxication
  • Transgenic plants

ASJC Scopus subject areas

  • Biotechnology
  • Biochemistry
  • Molecular Biology
  • Genetics

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