TY - JOUR
T1 - Mass spectrometry identifies covalent binding of soman, sarin, chlorpyrifos oxon, diisopropyl fluorophosphate, and FP-biotin to tyrosines on tubulin
T2 - A potential mechanism of long term toxicity by organophosphorus agents
AU - Grigoryan, Hasmik
AU - Schopfer, Lawrence M.
AU - Thompson, Charles M.
AU - Terry, Alvin V.
AU - Masson, Patrick
AU - Lockridge, Oksana
N1 - Funding Information:
Supported by U.S. Army Medical Research and Materiel Command W81XWH-07-2-0034 (to OL), W81XWH-06-1-0102, Eppley Cancer Center grant P30CA36727, DGA grant 03co010-05/PEA 01 08 7 to (PM), NIH/NIEHS) 1 R01 ES012241-01A1 (to AT), and NIH ES016102 (to CMT).
PY - 2008/9/25
Y1 - 2008/9/25
N2 - Chronic low dose exposure to organophosphorus poisons (OP) results in cognitive impairment. Studies in rats have shown that OP interfere with microtubule polymerization. Since microtubules are required for transport of nutrients from the nerve cell body to the nerve synapse, it has been suggested that disruption of microtubule function could explain the learning and memory deficits associated with OP exposure. Tubulin is a major constituent of microtubules. We tested the hypothesis that OP bind to tubulin by treating purified bovine tubulin with sarin, soman, chlorpyrifos oxon, diisopropylfluorophosphate, and 10-fluoroethoxyphosphinyl-N-biotinamidopentyldecanamide (FP-biotin). Tryptic peptides were isolated and analyzed by mass spectrometry. It was found that OP bound to tyrosine 83 of alpha tubulin in peptide TGTYR, tyrosine 59 in beta tubulin peptide YVPR, tyrosine 281 in beta tubulin peptide GSQQYR, and tyrosine 159 in beta tubulin peptide EEYPDR. The OP reactive tyrosines are located either near the GTP binding site or within loops that interact laterally with protofilaments. It is concluded that OP bind covalently to tubulin, and that this binding could explain cognitive impairment associated with OP exposure.
AB - Chronic low dose exposure to organophosphorus poisons (OP) results in cognitive impairment. Studies in rats have shown that OP interfere with microtubule polymerization. Since microtubules are required for transport of nutrients from the nerve cell body to the nerve synapse, it has been suggested that disruption of microtubule function could explain the learning and memory deficits associated with OP exposure. Tubulin is a major constituent of microtubules. We tested the hypothesis that OP bind to tubulin by treating purified bovine tubulin with sarin, soman, chlorpyrifos oxon, diisopropylfluorophosphate, and 10-fluoroethoxyphosphinyl-N-biotinamidopentyldecanamide (FP-biotin). Tryptic peptides were isolated and analyzed by mass spectrometry. It was found that OP bound to tyrosine 83 of alpha tubulin in peptide TGTYR, tyrosine 59 in beta tubulin peptide YVPR, tyrosine 281 in beta tubulin peptide GSQQYR, and tyrosine 159 in beta tubulin peptide EEYPDR. The OP reactive tyrosines are located either near the GTP binding site or within loops that interact laterally with protofilaments. It is concluded that OP bind covalently to tubulin, and that this binding could explain cognitive impairment associated with OP exposure.
KW - Mass spectrometer
KW - Nerve agent
KW - Organophosphate
KW - Tubulin
KW - Tyrosine
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U2 - 10.1016/j.cbi.2008.04.013
DO - 10.1016/j.cbi.2008.04.013
M3 - Article
C2 - 18502412
AN - SCOPUS:50649103273
SN - 0009-2797
VL - 175
SP - 180
EP - 186
JO - Chemico-Biological Interactions
JF - Chemico-Biological Interactions
IS - 1-3
ER -