Engineering Human PON1 in an E. coli Expression System
Expression and purification of recombinant human paraoxonase-1 (rHuPON1) from bacterial systems have proven elusive. Most systems for successful production of recombinant PON1 have relied on either eukaryotic expression in baculovirus or prokaryotic expression of synthetic, gene-shuffled rabbit–mouse–human PON1 hybrid molecules. We review here methods and protocols for the production of pure, native rHuPON1 using an E. coli expression system followed by conventional column chromatographic purification. The resulting rHuPON1 is stable, active, and capable of protecting PON1 knockout mice (PON1 –/– ) from exposure to high levels of the organophosphorus (OP) compound diazoxon. Bacterially-derived rHuPON1 can be produced in large quantities and lacks the glycosylation of eukaryotic systems that produces immunogenic complications when used as a therapeutic. The rHuPON1 should be useful for treating insecticide OP exposures and reducing risks of other diseases resulting from low PON1 status. The ease of mutagenesis in bacterial systems will also allow for the generation and screening of rHuPON1 variants with enhanced catalytic efficiencies against nerve agents and other OP compounds.
KeywordsRecombinant PON1 Nerve agents Diazoxon OP therapy Engineered PON1 E. coli expression PON1 knockout mice
This work was supported by National Institutes of Health Grants ES09883, ES04696, ES07033, and ES09601/EPA: RD-83170901, and a grant from the University of Washington Center for Process Analytical Chemistry (CFO1). This work was supported in part by the Defense Threat Reduction Agency (DEL, DMC and TCO). Opinions, interpretations, conclusions, and recommendations are those of the authors and are not necessarily endorsed by the US Army.
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