TY - JOUR
T1 - Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of titanium oxide-enriched peptides for detection of aged organophosphorus adducts on human butyrylcholinesterase
AU - Jiang, Wei
AU - Murashko, Ekaterina A.
AU - Dubrovskii, Yaroslav A.
AU - Podolskaya, Ekaterina P.
AU - Babakov, Vladimir N.
AU - Mikler, John
AU - Nachon, Florian
AU - Masson, Patrick
AU - Schopfer, Lawrence M.
AU - Lockridge, Oksana
N1 - Funding Information:
This work was supported by a Centers for Disease Control and Prevention contract (200-2012-M-53381 to O.L.), a National Institutes of Health grant (P30CA036727) to the Eppley Cancer Center directed by Kenneth Cowan, Direction Générale de l’Armement (DGA) of the French Ministry of Defense (DGA grants in support of Service de Santé des Armées 03co010-05 to P.M. and 08co501 to F.N.), Agence Nationale pour la Recherche (ANR-06-BLAN-0163 to F.N.), and a Russian Federal Medical–Biological Agency contract (25.442.12.0 to V.N.B.). Mass spectra were obtained with the support of the Mass Spectrometry and Proteomics Core Facility at the University of Nebraska Medical Center. The contents are solely the responsibility of the authors and do not necessarily represent the official views of the U.S., Russian, and/or French governments.
PY - 2013
Y1 - 2013
N2 - Exposure to nerve agents or organophosphorus (OP) pesticides can have life-threatening effects. Human plasma butyrylcholinesterase (BChE) inactivates these poisons by binding them to Ser198. After hours or days, these OP adducts acquire a negative charge by dealkylation in a process called aging. Our goal was to develop a method for enriching the aged adduct to facilitate detection of exposure. Human BChE inhibited by OP toxicants was incubated for 4 days to 6 years. Peptides produced by digestion with pepsin were enriched by binding to titanium oxide (TiO2) and analyzed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. It was found that with two exceptions, all aged OP adducts in peptide FGES 198AGAAS were enriched by binding to Titansphere tips. Cresyl saligenin phosphate yielded two types of aged adduct, cresylphosphate and phosphate, but only the phosphate adduct bound to Titansphere. The nerve agent VR yielded no aged adduct, supporting crystal structure findings that the VR adduct on BChE does not age. The irreversible nature of aged OP adducts was demonstrated by the finding that after 6 years at room temperature in sterile pH 7.0 buffer, the adducts were still detectable. It was concluded that TiO 2 microcolumns can be used to enrich aged OP-modified BChE peptide.
AB - Exposure to nerve agents or organophosphorus (OP) pesticides can have life-threatening effects. Human plasma butyrylcholinesterase (BChE) inactivates these poisons by binding them to Ser198. After hours or days, these OP adducts acquire a negative charge by dealkylation in a process called aging. Our goal was to develop a method for enriching the aged adduct to facilitate detection of exposure. Human BChE inhibited by OP toxicants was incubated for 4 days to 6 years. Peptides produced by digestion with pepsin were enriched by binding to titanium oxide (TiO2) and analyzed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. It was found that with two exceptions, all aged OP adducts in peptide FGES 198AGAAS were enriched by binding to Titansphere tips. Cresyl saligenin phosphate yielded two types of aged adduct, cresylphosphate and phosphate, but only the phosphate adduct bound to Titansphere. The nerve agent VR yielded no aged adduct, supporting crystal structure findings that the VR adduct on BChE does not age. The irreversible nature of aged OP adducts was demonstrated by the finding that after 6 years at room temperature in sterile pH 7.0 buffer, the adducts were still detectable. It was concluded that TiO 2 microcolumns can be used to enrich aged OP-modified BChE peptide.
KW - Aged organophosphorus adducts
KW - Human butyrylcholinesterase
KW - Mass spectrometry
KW - Titanium oxide
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U2 - 10.1016/j.ab.2013.04.018
DO - 10.1016/j.ab.2013.04.018
M3 - Article
C2 - 23624322
AN - SCOPUS:84879243247
SN - 0003-2697
VL - 439
SP - 132
EP - 141
JO - Analytical Biochemistry
JF - Analytical Biochemistry
IS - 2
ER -