Journal Article

FZJ-2022-05397

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png A novel binding site in the nicotinic acetylcholine receptor for MB327 can explain its allosteric modulation relevant for organophosphorus-poisoning treatment

Kaiser, J. ; Gertzen, C. G. W. ; Bernauer, T. ; Höfner, G. ; Niessen, K. V. ; Seeger, T. ; Paintner, F. F. ; Wanner, K. T. ; Worek, F. ; Thiermann, H. ; Gohlke, H. (Corresponding author)FZJ*

2023
Elsevier Science Amsterdam [u.a.]

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Please use a persistent id in citations: http://hdl.handle.net/2128/32994  doi:10.1016/j.toxlet.2022.11.018

Abstract: Organophosphorus compounds (OPCs) are highly toxic compounds that can block acetylcholine esterase (AChE) and thereby indirectly lead to an overstimulation of muscarinic and nicotinic acetylcholine receptors (nAChRs). The current treatment with atropine and AChE reactivators (oximes) is insufficient to prevent toxic effects, such as respiratory paralysis, after poisonings with various OPCs. Thus, alternative treatment options are required to increase treatment efficacy. Novel therapeutics, such as the bispyridinium non-oxime MB327, have been found to reestablish neuromuscular transmission by interacting directly with nAChR, probably via allosteric mechanisms. To rationally design new, more potent drugs addressing nAChR, knowledge of the binding mode of MB327 is fundamental. However, the binding pocket of MB327 has remained elusive. Here, we identify a new potential allosteric binding pocket (MB327-PAM-1) of MB327 located at the transition of the extracellular to the transmembrane region using blind docking experiments and molecular dynamics simulations. MB327 forms striking interactions with the receptor at this site. The interacting amino acids are highly conserved among different subunits and different species. Correspondingly, MB327 can interact with several nAChR subtypes from different species. We predict by rigidity analysis that MB327 exerts an allosteric effect on the orthosteric binding pocket and the transmembrane domain after binding to MB327-PAM-1. Furthermore, free ligand diffusion MD simulations reveal that MB327 also has an affinity to the orthosteric binding pocket, which agrees with recently published results that related bispyridinium compounds show inhibitory effects via the orthosteric binding site. The newly identified binding site allowed us to predict structural modifications of MB327, resulting in the more potent resensitizers PTM0062 and PTM0063.

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Contributing Institute(s):

1. John von Neumann - Institut für Computing (NIC)
2. Jülich Supercomputing Center (JSC)
3. Strukturbiochemie (IBI-7)
4. Bioinformatik (IBG-4)

Research Program(s):

1. 5111 - Domain-Specific Simulation & Data Life Cycle Labs (SDLs) and Research Groups (POF4-511) (POF4-511)
2. Forschergruppe Gohlke (hkf7_20200501) (hkf7_20200501)
3. 5241 - Molecular Information Processing in Cellular Systems (POF4-524) (POF4-524)

Appears in the scientific report 2023

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Database coverage:
; ; ; BIOSIS Previews ; Biological Abstracts ; Clarivate Analytics Master Journal List ; Current Contents - Life Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF < 5 ; JCR ; Nationallizenz ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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