Molecular Modeling Studies on the Multistep Reactivation Process of Organophosphate-Inhibited Acetylcholinesterase and Butyrylcholinesterase

Poisoning with organophosphorus compounds used as pesticides or misused as chemical weapons remains a serious threat to human health and life. Their toxic effects result from irreversible blockade of the enzymes acetylcholinesterase and butyrylcholinesterase, which causes overstimulation of the cholinergic system and often leads to serious injury or death. Treatment of organophosphorus poisoning involves, among other strategies, the administration of oxime compounds. Oximes reactivate cholinesterases by breaking the covalent bond between the serine residue from the enzyme active site and the phosphorus atom of the organophosphorus compound. Although the general mechanism of reactivation has been known for years, the exact molecular aspects determining the efficiency and selectivity of individual oximes are still not clear. This hinders the development of new active compounds. In our research, using relatively simple and widely available molecular docking methods, we investigated the reactivation of acetyl- and butyrylcholinesterase blocked by sarin and tabun. For the selected oximes, their binding modes at each step of the reactivation process were identified. Amino acids essential for effective reactivation and those responsible for the selectivity of individual oximes against inhibited acetyl- and butyrylcholinesterase were identified. This research broadens the knowledge about cholinesterase reactivation and demonstrates the usefulness of molecular docking in the study of this process. The presented observations and methods can be used in the future to support the search for new effective reactivators.

[1]  K. Kuča,et al.  Reactivation of VX-Inhibited Human Acetylcholinesterase by Deprotonated Pralidoxime. A Complementary Quantum Mechanical Study , 2020, Biomolecules.

[2]  K. Kuča,et al.  Synthesis, in vitro screening and molecular docking of isoquinolinium-5-carbaldoximes as acetylcholinesterase and butyrylcholinesterase reactivators , 2020, Journal of enzyme inhibition and medicinal chemistry.

[3]  K. Kuča,et al.  Reactivation potency of two novel oximes (K456 and K733) against paraoxon-inhibited acetyl and butyrylcholinesterase: In silico and in vitro models. , 2019, Chemico-biological interactions.

[4]  K. Kuča,et al.  Slight difference in the isomeric oximes K206 and K203 makes huge difference for the reactivation of organophosphorus-inhibited AChE: Theoretical and experimental aspects. , 2019, Chemico-biological interactions.

[5]  K. Kuča,et al.  Butyrylcholinesterase inhibited by nerve agents is efficiently reactivated with chlorinated pyridinium oximes. , 2019, Chemico-biological interactions.

[6]  D. Blumenthal,et al.  Productive reorientation of a bound oxime reactivator revealed in room temperature X-ray structures of native and VX-inhibited human acetylcholinesterase , 2019, The Journal of Biological Chemistry.

[7]  M. Eddleston Novel Clinical Toxicology and Pharmacology of Organophosphorus Insecticide Self-Poisoning. , 2019, Annual review of pharmacology and toxicology.

[8]  K. Kuča,et al.  Molecular modeling studies on the interactions of 7-methoxytacrine-4-pyridinealdoxime, 4-PA, 2-PAM, and obidoxime with VX-inhibited human acetylcholinesterase: a near attack conformation approach , 2019, Journal of enzyme inhibition and medicinal chemistry.

[9]  P. Masson,et al.  6-Methyluracil derivatives as peripheral site ligand-hydroxamic acid conjugates: Reactivation for paraoxon-inhibited acetylcholinesterase. , 2019, European journal of medicinal chemistry.

[10]  K. Kuča,et al.  Oxime K203: a drug candidate for the treatment of tabun intoxication , 2018, Archives of Toxicology.

[11]  M. Guelta,et al.  Structural Insights of Stereospecific Inhibition of Human Acetylcholinesterase by VX and Subsequent Reactivation by HI-6. , 2018, Chemical research in toxicology.

[12]  M. Valis,et al.  A newly developed oxime K203 is the most effective reactivator of tabun-inhibited acetylcholinesterase , 2018, BMC Pharmacology and Toxicology.

[13]  E. Boyer,et al.  Novichok agents: a historical, current, and toxicological perspective , 2018, Toxicology communications.

[14]  D. Noort,et al.  Fatal sarin poisoning in Syria 2013: forensic verification within an international laboratory network , 2017, Forensic Toxicology.

[15]  Bishwajit Ganguly,et al.  Revealing the importance of linkers in K-series oxime reactivators for tabun-inhibited AChE using quantum chemical, docking and SMD studies , 2017, Journal of Computer-Aided Molecular Design.

[16]  C. Ginter,et al.  Structures of paraoxon‐inhibited human acetylcholinesterase reveal perturbations of the acyl loop and the dimer interface , 2016, Proteins.

[17]  R. Ochoa,et al.  Perspectives for the structure-based design of acetylcholinesterase reactivators. , 2016, Journal of molecular graphics & modelling.

[18]  A. Linusson,et al.  Structure of a prereaction complex between the nerve agent sarin, its biological target acetylcholinesterase, and the antidote HI-6 , 2016, Proceedings of the National Academy of Sciences.

[19]  B. Ganguly,et al.  The reactivation of tabun-inhibited mutant AChE with Ortho-7: steered molecular dynamics and quantum chemical studies. , 2016, Molecular bioSystems.

[20]  J. Moran,et al.  Clinical features of organophosphate poisoning: A review of different classification systems and approaches , 2014, Indian journal of critical care medicine : peer-reviewed, official publication of Indian Society of Critical Care Medicine.

[21]  Yingkai Zhang,et al.  How Is Acetylcholinesterase Phosphonylated by Soman? An Ab Initio QM/MM Molecular Dynamics Study , 2014, The journal of physical chemistry. A.

[22]  Woody Sherman,et al.  Protein and ligand preparation: parameters, protocols, and influence on virtual screening enrichments , 2013, Journal of Computer-Aided Molecular Design.

[23]  C. Sotriffer,et al.  Structure-Based Search for New Inhibitors of Cholinesterases , 2013, International journal of molecular sciences.

[24]  P. Renard,et al.  Reactivators of acetylcholinesterase inhibited by organophosphorus nerve agents. , 2012, Accounts of chemical research.

[25]  K. Kuča,et al.  Pseudo-catalytic scavenging: searching for a suitable reactivator of phosphorylated butyrylcholinesterase. , 2010, Chemico-biological interactions.

[26]  P. Masson,et al.  Aging mechanism of butyrylcholinesterase inhibited by an N-methyl analogue of tabun: implications of the trigonal-bipyramidal transition state rearrangement for the phosphylation or reactivation of cholinesterases. , 2010, Chemico-biological interactions.

[27]  J. Koča,et al.  Why acetylcholinesterase reactivators do not work in butyrylcholinesterase , 2010, Journal of enzyme inhibition and medicinal chemistry.

[28]  P. Masson,et al.  Structure-activity analysis of aging and reactivation of human butyrylcholinesterase inhibited by analogues of tabun. , 2009, The Biochemical journal.

[29]  K. Kuča,et al.  Evaluation of Oxime K203 as Antidote in Tabun Poisoning , 2009, Arhiv za higijenu rada i toksikologiju.

[30]  K. Kuča,et al.  In vitro reactivation potency of acetylcholinesterase reactivators — K074 and K075 — to reactivate tabun-inhibited human brain cholinesterases , 2007, Neurotoxicity Research.

[31]  M. Froment,et al.  Aging of cholinesterases phosphylated by tabun proceeds through O-dealkylation. , 2008, Journal of the American Chemical Society.

[32]  K. Kuča,et al.  A comparison of reactivating efficacy of newly developed oximes (K074, K075) and currently available oximes (obidoxime, HI-6) in soman, cyclosarin and tabun-poisoned rats. , 2008, Chemico-biological interactions.

[33]  David Gunnell,et al.  The global distribution of fatal pesticide self-poisoning: Systematic review , 2007, BMC public health.

[34]  F. Worek,et al.  Enzyme-kinetic investigation of different sarin analogues reacting with human acetylcholinesterase and butyrylcholinesterase. , 2007, Toxicology.

[35]  F. Ekström,et al.  Crystal structures of acetylcholinesterase in complex with organophosphorus compounds suggest that the acyl pocket modulates the aging reaction by precluding the formation of the trigonal bipyramidal transition state. , 2007, Biochemistry.

[36]  M. Jokanović,et al.  Current understanding of the application of pyridinium oximes as cholinesterase reactivators in treatment of organophosphate poisoning. , 2006, European journal of pharmacology.

[37]  K. Kuča,et al.  Pretreatment with pyridinium oximes improves antidotal therapy against tabun poisoning. , 2006, Toxicology.

[38]  N. Greig,et al.  In vitro and in vivo characterization of recombinant human butyrylcholinesterase (Protexia) as a potential nerve agent bioscavenger. , 2005, Chemico-biological interactions.

[39]  Elizabeth Bridges,et al.  The Sarin Gas Attacks on the Tokyo Subway - 10 years later/Lessons Learned , 2005 .

[40]  J. Newmark Therapy for nerve agent poisoning. , 2004, Archives of neurology.

[41]  Y. Ashani,et al.  Inhibition of cholinesterases with cationic phosphonyl oximes highlights distinctive properties of the charged pyridine groups of quaternary oxime reactivators. , 2003, Biochemical pharmacology.

[42]  J. Kassa,et al.  Review of Oximes in the Antidotal Treatment of Poisoning by Organophosphorus Nerve Agents , 2002, Journal of toxicology. Clinical toxicology.

[43]  P. Taylor,et al.  Phosphoryl oxime inhibition of acetylcholinesterase during oxime reactivation is prevented by edrophonium. , 1999, Biochemistry.

[44]  P Willett,et al.  Development and validation of a genetic algorithm for flexible docking. , 1997, Journal of molecular biology.

[45]  T. R. Fukuto,et al.  Mechanism of action of organophosphorus and carbamate insecticides. , 1990, Environmental health perspectives.