TY - JOUR
T1 - Identification of carboxylesterase, butyrylcholinesterase, acetylcholinesterase, paraoxonase, and albumin pseudoesterase in Guinea pig plasma through nondenaturing gel electrophoresis
AU - Napon, Geoffroy
AU - Dafferner, Alicia J.
AU - Saxena, Ashima
AU - Lockridge, Oksana
N1 - Funding Information:
GN was supported by the Urban Health Opportunities Program administered through the University of Nebraska Omaha, where he is an undergraduate student. This work was supported by the Defense Threat Reduction Agency 140003_04_WR_C (to AS) and the Fred and Pamela Buffett Cancer Center Support Grant P30CA036727 from NIH. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army or the Department of Defense.
Funding Information:
GN was supported by the Urban Health Opportunities Program administered through the University of Nebraska Omaha, where he is an undergraduate student. This work was supported by the Defense Threat Reduction Agency 140003_04_WR_C (to AS) and the Fred and Pamela Buffett Cancer Center Support Grant P30CA036727 from NIH.
Publisher Copyright:
© 2018 American Association Lab. Anim. Sci.. All rights reserved.
PY - 2018/10
Y1 - 2018/10
N2 - Drugs to protect against nerve agent toxicity are tested in animals. The current preferred small animal model is Guinea pigs because their plasma bioscavenging capacity resembles that of NHP. We stained nondenaturing polyacrylamide slab gels with a variety of substrates, inhibitors, and antibodies to identify the esterases in heparinized Guinea pig plasma. An intense band of carboxylesterase activity migrated behind albumin. Minor carboxylesterase bands were revealed after background activity from paraoxonase was inhibited by using EDTA. The major butyrylcholinesterase band was a disulfide-linked dimer. Incubation with the antihuman butyrylcholinesterase antibody B2 18-5 shifted the butyrylcholinesterase dimer band to slower migrating complexes. Carboxylesterases were distinguished from butyrylcholinesterase by their sensitivity to inhibition by bis-p-nitrophenyl phosphate. Acetylcholinesterase tetramers formed a complex with the antihuman acetylcholinesterase antibody HR2. Organophosphorus toxicants including cresyl saligenin phosphate, dichlorvos, and chlorpyrifos oxon irreversibly inhibited the serine esterases but not paraoxonase. Albumin pseudoesterase activity was seen in gels stained with α- or β-naphthyl acetate and fast blue RR. We conclude that Guinea pig plasma has 2 types of carboxylesterase, butyrylcholinesterase dimers and 5 minor butyrylcholinesterase forms, a small amount of acetylcholinesterase tetramers, paraoxonase, and albumin pseudoesterase activity. A knockout mouse with no carboxylesterase activity in plasma is available and may prove to be a better model for studies of nerve agent toxicology than Guinea pigs.
AB - Drugs to protect against nerve agent toxicity are tested in animals. The current preferred small animal model is Guinea pigs because their plasma bioscavenging capacity resembles that of NHP. We stained nondenaturing polyacrylamide slab gels with a variety of substrates, inhibitors, and antibodies to identify the esterases in heparinized Guinea pig plasma. An intense band of carboxylesterase activity migrated behind albumin. Minor carboxylesterase bands were revealed after background activity from paraoxonase was inhibited by using EDTA. The major butyrylcholinesterase band was a disulfide-linked dimer. Incubation with the antihuman butyrylcholinesterase antibody B2 18-5 shifted the butyrylcholinesterase dimer band to slower migrating complexes. Carboxylesterases were distinguished from butyrylcholinesterase by their sensitivity to inhibition by bis-p-nitrophenyl phosphate. Acetylcholinesterase tetramers formed a complex with the antihuman acetylcholinesterase antibody HR2. Organophosphorus toxicants including cresyl saligenin phosphate, dichlorvos, and chlorpyrifos oxon irreversibly inhibited the serine esterases but not paraoxonase. Albumin pseudoesterase activity was seen in gels stained with α- or β-naphthyl acetate and fast blue RR. We conclude that Guinea pig plasma has 2 types of carboxylesterase, butyrylcholinesterase dimers and 5 minor butyrylcholinesterase forms, a small amount of acetylcholinesterase tetramers, paraoxonase, and albumin pseudoesterase activity. A knockout mouse with no carboxylesterase activity in plasma is available and may prove to be a better model for studies of nerve agent toxicology than Guinea pigs.
KW - BNPP
KW - Bis-nitrophenyl phosphate
KW - CBDP
KW - Cresyl saligenin phosphate
KW - HuBChE
KW - Human butyrylcholinesterase
KW - Tetraisopropyl pyrophosphoramide
KW - isoOMPA
UR - http://www.scopus.com/inward/record.url?scp=85055629677&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85055629677&partnerID=8YFLogxK
U2 - 10.30802/AALAS-CM-18-000047
DO - 10.30802/AALAS-CM-18-000047
M3 - Article
C2 - 30278860
AN - SCOPUS:85055629677
SN - 1532-0820
VL - 68
SP - 367
EP - 374
JO - Comparative Medicine
JF - Comparative Medicine
IS - 5
ER -