Evidence map›Paper›PMID 22778816›Full record

ArticleACS chemical neuroscience2010

Identifying the binding site of novel methyllycaconitine (MLA) analogs at α4β2 nicotinic acetylcholine receptors.

Gracia X J Quek, Diana Lin, Jill I Halliday, Nathan Absalom, Joseph I Ambrus, Andrew J Thompson, Martin Lochner, Sarah C R Lummis, Malcolm D McLeod, Mary Chebib

Abstract read
In one paragraph

Article in ACS chemical neuroscience, 2010. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.

0numbers the graph read from it
0cells of the map it votes in
4citing papers in PubMed
0.4field-weighted citation impact, top 37% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

4 citing papers in PubMed, 11 citations in OpenAlex.

  1. Article
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  4. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

10 authors at 4 institutions in 3 countries.

Gracia X J QuekFaculty of Pharmacy, The University of Sydney, Australia.
Diana Lin
Jill I Halliday
Nathan Absalom
Joseph I Ambrus
Andrew J Thompson
Martin Lochner
Sarah C R Lummis
Malcolm D McLeod
Mary Chebib
University of Sydney · AUAustralian National University · AUUniversity of Cambridge · GBUniversity of Bern · CH

Funding

Wellcome Trust
6 · The paper itself

Abstract

Neuronal nicotinic acetylcholine receptors (nAChR) are ligand gated ion channels that mediate fast synaptic transmission. Methyllycaconitine (MLA) is a selective and potent antagonist of the α7 nAChR, and its anthranilate ester side-chain is important for its activity. Here we report the influence of structure on nAChR inhibition for a series of novel MLA analogs, incorporating either an alcohol or anthranilate ester side-chain to an azabicyclic or azatricyclic core against rat α7, α4β2, and α3β4 nAChRs expressed in Xenopus oocytes. The analogs inhibited ACh (EC(50)) within an IC(50) range of 2.3-26.6 μM. Most displayed noncompetitive antagonism, but the anthranilate ester analogs exerted competitive behavior at the α7 nAChR. At α4β2 nAChRs, inhibition by the azabicyclic alcohol was voltage-dependent suggesting channel block. The channel-lining residues of α4 subunits were mutated to cysteine and the effect of azabicyclic alcohol was evaluated by competition with methanethiosulfonate ethylammonium (MTSEA) and a thiol-reactive probe in the open, closed, and desensitized states of α4β2 nAChRs. The azabicyclic alcohol was found to compete with MTSEA between residues 6' and 13' in a state-dependent manner, but the reactive probe only bonded with 13' in the open state. The data suggest that the 13' position is the dominant binding site. Ligand docking of the azabicyclic alcohol into a (α4)(3)(β2)(2) homology model of the closed channel showed that the ligand can be accommodated at this location. Thus our data reveal distinct pharmacological differences between different nAChR subtypes and also identify a specific binding site for a noncompetitive channel blocker.

Indexed as

Aconitinealpha7 Nicotinic Acetylcholine ReceptorAmino Acid SubstitutionAnimalsBinding SitesCysteineDose-Response Relationship, DrugEthyl MethanesulfonateFemaleMembrane PotentialsModels, ChemicalModels, MolecularMolecular StructureMustard CompoundsMutagenesis, Site-DirectedOocytesAconitinealpha7 Nicotinic Acetylcholine ReceptorChrna7 protein, ratCysteineEthyl Methanesulfonatemethanethiosulfonate ethylammoniummethyllycaconitineMustard Compoundsnicotinic receptor alpha3beta4nicotinic receptor alpha4beta2Receptors, NicotinicRecombinant Proteinshomology modelLigand-gated ion channel (LGIC)methyllycaconitine (MLA)nicotinic acetylcholine receptor (nAChR)noncompetitive antagonist (NCA)reactive probesubstituted cysteine accessibility method (SCAM)

Identifiers

PMID22778816
PMCPMC3368652
OpenAlexW2083920349

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.