6533b835fe1ef96bd129ebf2
RESEARCH PRODUCT
Desensitization is a property of the cholinergic binding region of the nicotinic acetylcholine receptor, not of the receptor-integral ion channel
Jürgen KuhlmannAlfred MaelickeKehinde O. Okonjosubject
Nicotinic acetylcholine receptorStereochemistryAcetylcholine-gated cation channelPhysostigmineBiophysicsCesiumIon fluxDesensitizationIn Vitro TechniquesReceptors NicotinicTorpedoBiochemistryIon ChannelsAnticholinesteraseAcetylcholine bindingGanglion type nicotinic receptorStructural BiologyMuscarinic acetylcholine receptor M5GeneticsmedicineAnimalsMolecular BiologyAcetylcholine receptorBinding SitesChemistryCell BiologyBungarotoxinsAcetylcholineNicotinic acetylcholine receptorNicotinic agonistCarbamateBiophysicsCholinergicAcetylcholineEserinemedicine.drugdescription
AbstractThe reversible acetylcholine esterase inhibitor (−)-physostigmine (eserine) is the prototype of a new class of nicotinic acetylcholine receptor (nAChR) activating ligands: it induces cation fluxes into nAChR-rich membrane vesicles from Torpedo marmorala electric tissue even under conditions of antagonist blocked acetylcholine binding sites (Okonjo, Kuhlmann, Maclicke, Neuron, in press). This suggests that eserine exerts its channel-activating property via binding sites at the nAChR separate from those of the natural transmitter. We now report that eserine can activate the channel even when the receptor has been preincubated (desensitized) with elevated concentrations of acetylcholine. Thus the conformational state of the receptor corresponding to desensitization is confined to the transmitter binding region, leaving the channel fully activatable — albeit only from other than the transmitter binding site(s).
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1991-02-25 | FEBS Letters |