The inhibition, reactivation and mechanism of VX-, sarin-, fluoro-VX and fluoro-sarin surrogates following their interaction with HuAChE and HuBuChE.
The inhibition, reactivation and mechanism of VX-, sarin-, fluoro-VX and fluoro-sarin surrogates following their interaction with HuAChE and HuBuChE.
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DOI：
10.1016/j.cbi.2018.06.019
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发表时间：
2018-08-01
影响因子：
5.1
通讯作者：
Thompson CM
中科院分区：
文献类型：
--
作者：
Chao CK;Balasubramanian N;Gerdes JM;Thompson CM
In this study, the mechanisms of HuAChE and HuBChE inhibition by Me-P(O)(OPNP)(OR) [PNP = p-nitrophenyl; R = CH2CH3, CH2CH2F, OCH(CH3)2, OCH(CH3)(CH2F)] representing surrogates and fluoro-surrogates of VX and sarin were studied by in vitro kinetics and mass spectrometry. The in vitro measures showed that the VX- and fluoro-VX surrogates were relatively strong inhibitors of HuAChE and HuBChE (ki ~ 105−106 M−1min−1) and underwent spontaneous and 2-PAM-mediated reactivation within 30 min. The sarin surrogates were weaker inhibitors of HuAChE and HuBChE (ki ~ 104−105 M−1min−1), and in general did not undergo spontaneous reactivation, although HuAChE adducts were partially reactivatable at 18 h using 2-PAM. The mechanism of HuAChE and HuBChE inhibition by the surrogates was determined by Q-TOF and MALDI-TOF mass spectral analyses. The surrogate-adducted proteins were trypsin digested and the active site-containing peptide bearing the OP-modified serine identified by Q-TOF as triply- and quadruply-charged ions representing the respective increase in mass of the attached OP moiety. Correspondingly, monoisotopic ions of the tryptic peptides representing the mass increase of the OP-adducted peptide was identified by MALDI-TOF. The mass spectrometry analyses validated the identity of the OP moiety attached to HuAChE or HuBChE as MeP(O)(OR)-O-serine peptides (loss of the PNP leaving group) via mechanisms consistent with those found with chemical warfare agents. MALDI-TOF MS analyses of the VX-modified peptides versus time showed a steady reduction in adduct versus parent peptide (reactivation), whereas the sarin-surrogate-modified peptides remained largely intact over the course of the experiment (24 h). Overall, the presence of a fluorine atom on the surrogate modestly altered the rate constants of inhibition and reactivation, however, the mechanism of inhibition (ejection of PNP group) did not change.
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影响因子：
5.8
作者：
ELLMAN, GL;COURTNEY, KD;FEATHERSTONE, RM
通讯作者：
FEATHERSTONE, RM
影响因子：
4.1
作者：
Gilley, Cynthia;MacDonald, Mary;Lockridge, Oksana
通讯作者：
Lockridge, Oksana
影响因子：
3.8
作者：
Peeples, ES;Schopfer, LM;Lockridge, O
通讯作者：
Lockridge, O
影响因子：
2.9
作者：
RADIC, Z;PICKERING, NA;TAYLOR, P
通讯作者：
TAYLOR, P
影响因子：
3.5
作者：
Coban, Alper;Carr, Russell L.;Chambers, Janice E.
通讯作者：
Chambers, Janice E.