title: Targeting of organophosphorus compound bioscavengers to the surface of red blood cells.
abstract: To develop a prophylactic for organophosphorus (OP) poisoning utilizing catalytic bioscavengers, the circulatory stability of the enzymes needs to be increased. One strategy for increasing the bioavailability of OP bioscavengers is to target them to the surface of red blood cells (RBCs). Given the circulatory lifespan of 120 days for human RBCs, this strategy has the potential for creating a persistent pool of bioscavenger. Here we report the development of fusion proteins with a single chain variable fragment (scFv) of Ter119, a molecule that associates with glycophorin A on the surface of RBCs, and the VIID11 variant of paraoxonase 1 (scFv-PON1). We show that scFv-PON1 variants expressed by Trichoplusia ni larvae are catalytically active and that one variant in particular can successfully bind to the surface of murine RBCs both in vitro and in vivo. This study represents a proof of concept for targeting catalytic bioscavengers to the surface of RBCs and is an early step in developing catalytic bioscavengers that can remain in circulation for an extended period of time.
authors.affiliation: US Army Medical Research Institute of Chemical Defense, 2900 Ricketts Point Rd., Aberdeen Proving Ground, MD, 21010, United States. Electronic address: bryan.j.mccranor.ctr@mail.mil.
authors.forename: Bryan J
authors.initials: BJ
authors.lastname: McCranor
authors.affiliation: US Army Medical Research Institute of Chemical Defense, 2900 Ricketts Point Rd., Aberdeen Proving Ground, MD, 21010, United States.
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Hofstetter
authors.affiliation: US Army Medical Research Institute of Chemical Defense, 2900 Ricketts Point Rd., Aberdeen Proving Ground, MD, 21010, United States.
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Olert
authors.affiliation: US Army Medical Research Institute of Chemical Defense, 2900 Ricketts Point Rd., Aberdeen Proving Ground, MD, 21010, United States.
authors.forename: Deborah
authors.initials: D
authors.lastname: Moorad-Doctor
authors.affiliation: US Army Medical Research Institute of Chemical Defense, 2900 Ricketts Point Rd., Aberdeen Proving Ground, MD, 21010, United States.
authors.forename: Douglas M
authors.initials: DM
authors.lastname: Cerasoli
authors.affiliation: US Army Medical Research Institute of Chemical Defense, 2900 Ricketts Point Rd., Aberdeen Proving Ground, MD, 21010, United States.
authors.forename: Gregory E
authors.initials: GE
authors.lastname: Garcia
mesh_terms: D000818:Animals; D043303:Aryldialkylphosphatase / Q000097:blood / Q000378:metabolism; D055162:Biocatalysis; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008810:Mice, Inbred C57BL; D009943:Organophosphorus Compounds / Q000633:toxicity*; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D009943:Organophosphorus Compounds; D011993:Recombinant Fusion Proteins; D043303:Aryldialkylphosphatase
keywords: Bioscavenger; Glycophorin A; Organophosphorus; Paraoxonase-1; Red blood cells; Single chain variable fragment