TY  - JOUR
AU  - Kaiser, Jesko
AU  - Gertzen, Christoph G. W.
AU  - Bernauer, Tamara
AU  - Höfner, Georg
AU  - Niessen, Karin V.
AU  - Seeger, Thomas
AU  - Paintner, Franz F.
AU  - Wanner, Klaus T.
AU  - Worek, Franz
AU  - Thiermann, Horst
AU  - Gohlke, Holger
TI  - A novel binding site in the nicotinic acetylcholine receptor for MB327 can explain its allosteric modulation relevant for organophosphorus-poisoning treatment
JO  - Toxicology letters
VL  - 373
SN  - 0378-4274
CY  - Amsterdam [u.a.]
PB  - Elsevier Science
M1  - FZJ-2022-05397
SP  - 160-171
PY  - 2023
AB  - 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.
LB  - PUB:(DE-HGF)16
C6  - 36503818
UR  - <Go to ISI:>//WOS:000928240000002
DO  - DOI:10.1016/j.toxlet.2022.11.018
UR  - https://juser.fz-juelich.de/record/912181
ER  -