In vitro characterization of cationic copolymer-complexed recombinant human butyrylcholinesterase

Carey Pope, Chibuzor Uchea, Nicholas Flynn, Kirstin Poindexter, Liyi Geng, William Stephen Brimijoin, Steve Hartson, Ashish Ranjan, Joshua D. Ramsey, Jing Liu

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Effective use of exogenous human BChE as a bioscavenger for organophosphorus toxicants (OPs) is hindered by its limited availability and rapid clearance. Complexes made from recombinant human BChE (rhBChE) and copolymers may be useful in addressing these problems. We used in vitro approaches to compare enzyme activity, sensitivity to inhibition, stability and bioscavenging capacity of free enzyme and copolymer-rhBChE complexes (C-BCs) based on one of nine different copolymers, from combinations of three molecular weights (MW) of poly-l-lysine (PLL; high MW, 30-70 kDa; medium MW, 15-30 kDa; low MW, 4-15 kDa) and three grafting ratios of poly(ethylene glycol) (PEG; 2:1, 10:1, 20:1). Retarded protein migration into acrylamide gels stained for BChE activity was noted with all copolymers as the copolymer-to-protein ratio was increased. BChE activity of C-BCs was lower relative to free enzyme, with the 2:1 grafting ratio showing generally greater reduction. Free enzyme and C-BCs showed relatively similar in vitro sensitivity to inhibition by paraoxon, but use of the 20:1 grafting ratio led to lower potencies. Through these screening assays we selected three C-BCs (high, medium and low MW; 10:1 grafting) for further characterizations. BChE activity was higher in C-BCs made with the medium and low compared to high MW-based copolymer. C-BCs generally showed higher stability than free enzyme when maintained for long periods at 37 °C or following incubation with chymotrypsin. Free enzyme and C-BCs were similarly effective at inactivating paraoxon in vitro. While these results are promising for further development, additional studies are needed to evaluate in vivo performance.

Original languageEnglish (US)
Pages (from-to)531-539
Number of pages9
JournalBiochemical Pharmacology
Volume98
Issue number3
DOIs
StatePublished - Dec 1 2015

Fingerprint

Butyrylcholinesterase
Copolymers
Molecular Weight
Paraoxon
Enzymes
Molecular weight
Enzyme Stability
Ethylene Glycol
Acrylamide
Chymotrypsin
Polyethylene glycols
Lysine
In Vitro Techniques
Proteins
Gels
Enzyme inhibition
Enzyme activity
Phase locked loops
Assays
Screening

Keywords

  • Bioscavenger
  • Nerve agent
  • Organophosphate
  • Paraoxon

ASJC Scopus subject areas

  • Biochemistry
  • Pharmacology

Cite this

In vitro characterization of cationic copolymer-complexed recombinant human butyrylcholinesterase. / Pope, Carey; Uchea, Chibuzor; Flynn, Nicholas; Poindexter, Kirstin; Geng, Liyi; Brimijoin, William Stephen; Hartson, Steve; Ranjan, Ashish; Ramsey, Joshua D.; Liu, Jing.

In: Biochemical Pharmacology, Vol. 98, No. 3, 01.12.2015, p. 531-539.

Research output: Contribution to journalArticle

Pope, C, Uchea, C, Flynn, N, Poindexter, K, Geng, L, Brimijoin, WS, Hartson, S, Ranjan, A, Ramsey, JD & Liu, J 2015, 'In vitro characterization of cationic copolymer-complexed recombinant human butyrylcholinesterase', Biochemical Pharmacology, vol. 98, no. 3, pp. 531-539. https://doi.org/10.1016/j.bcp.2015.10.005
Pope, Carey ; Uchea, Chibuzor ; Flynn, Nicholas ; Poindexter, Kirstin ; Geng, Liyi ; Brimijoin, William Stephen ; Hartson, Steve ; Ranjan, Ashish ; Ramsey, Joshua D. ; Liu, Jing. / In vitro characterization of cationic copolymer-complexed recombinant human butyrylcholinesterase. In: Biochemical Pharmacology. 2015 ; Vol. 98, No. 3. pp. 531-539.
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AU - Brimijoin, William Stephen

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