title: Polyethylene-glycol conjugated recombinant human acetylcholinesterase serves as an efficacious bioscavenger against soman intoxication.
abstract: Extensive pharmacokinetic studies in both mice and rhesus macaques, with biochemically well defined forms of native and recombinant AChEs from bovine, rhesus and human origin, allowed us to determine an hierarchical pattern by which post-translation-related factors and specific amino-acid epitopes govern the pharmacokinetic performance of the enzyme molecule. In parallel, we demonstrated that controlled conjugation of polyethylene-glycol (PEG) side-chains to lysine residues of rHuAChE also results in the generation of active enzyme with improved pharmacokinetic performance. Here, we show that equally efficient extension of circulatory residence can be achieved by specific conditions of PEGylation, regardless of the post-translation-modification state of the enzyme. The masking effect of PEGylation, which is responsible for extending circulatory lifetime, also contributes to the elimination of immunological responses following repeated administration of AChE. Finally, in vivo protection studies in mice allowed us to determine that the PEGylated AChE protects the animal from a high lethal dose (2.5 LD(50)) of soman. On a mole basis, both the recombinant AChE and its PEGylated form provide higher levels of protection against soman poisoning than the native serum-derived HuBChE. The findings that circulatory long-lived PEGylated AChE can confer superior protection to mice against OP-compound poisoning while exhibiting reduced immunogenicity, suggest that this chemically modified version of rHuAChE may serve as a highly effective bioscavenger for prophylactic treatment against OP-poisoning.
authors.affiliation: Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 74100, Israel.
authors.forename: Chanoch
authors.initials: C
authors.lastname: Kronman
authors.forename: Ofer
authors.initials: O
authors.lastname: Cohen
authors.forename: Lily
authors.initials: L
authors.lastname: Raveh
authors.forename: Ohad
authors.initials: O
authors.lastname: Mazor
authors.forename: Arie
authors.initials: A
authors.lastname: Ordentlich
authors.forename: Avigdor
authors.initials: A
authors.lastname: Shafferman
mesh_terms: D000110:Acetylcholinesterase / Q000009:adverse effects / Q000096:biosynthesis / Q000737:chemistry / Q000493:pharmacokinetics; D000818:Animals; D000906:Antibodies / Q000097:blood; D002460:Cell Line; D002800:Cholinesterase Inhibitors / Q000633:toxicity*; D003001:Cloning, Molecular; D004337:Drug Carriers / Q000737:chemistry*; D004797:Enzyme-Linked Immunosorbent Assay; D006207:Half-Life; D006801:Humans; D007928:Lethal Dose 50; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D018696:Neuroprotective Agents / Q000009:adverse effects / Q000737:chemistry / Q000493:pharmacokinetics; D020258:Neurotoxicity Syndromes / Q000517:prevention & control*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011994:Recombinant Proteins / Q000009:adverse effects / Q000096:biosynthesis / Q000493:pharmacokinetics; D012999:Soman / Q000633:toxicity*; D013379:Substrate Specificity
chemical_list: D000906:Antibodies; D002800:Cholinesterase Inhibitors; D004337:Drug Carriers; D018696:Neuroprotective Agents; D011994:Recombinant Proteins; D011092:Polyethylene Glycols; D012999:Soman; D000110:Acetylcholinesterase