Model acetylcholinesterase-Fc fusion glycoprotein biotechnology system for the manufacture of an organophosphorus toxicant bioscavenging countermeasure

Abstract

Organophosphate (OP) toxicants remain an active threat to public health and to warfighters in the military. Current countermeasures require near immediate administration following OP exposure and are reported to have controversial efficacies. Acetylcholinesterase (AChE) fused to the human immunoglobulin 1 (IgG1) Fc domain (AChE-Fc) is a potential bioscavenger for OP toxicants, but a reproducible AChE-Fc biomanufacturing strategy remains elusive. This report is the first to establish a comprehensive laboratory-scale bioprocessing strategy that can reproducibly produce AChE-Fc and AChE(W86A)-Fc which is a mutated AChE protein with reduced enzymatic activity. Characterization studies revealed that AChE-Fc and AChE(W86A)-Fc are N-glycosylated dimeric fusion glycoproteins but only AChE-Fc had the capability to bind to paraoxon (a model OP). This AChE-Fc fusion glycoprotein bioprocessing strategy can be leveraged during industrial biomanufacturing development, while the research-grade AChE-Fc proteins can be used to determine the potential clinical relevance of the countermeasure against OP toxicants.