Desensitization is a property of the cholinergic binding region of the nicotinic acetylcholine receptor, not of the receptor‐integral ion channel

FEBS Letters

Kuhlmann, Jürgen¹  Maelicke, Alfred¹  Okonjo, Kehinde O.¹ 

[1] Institute of Physiological Chemistry, Johannes-Gutenberg University Medical School, 6 Duesbergweg, D-6500 Mainz, Germany

关键词: Nicotinic acetylcholine receptor;    Acetylcholine-gated cation channel;    Desensitization;    Ion flux;    Carbamate;    Physostigmine;    Eserine;    Anticholinesterase;    ACh;    acetylcholine;    AChE;    acetylcholine esterase;    nAChR;    nicotinic acetylcholine receptor;   

DOI  :  10.1016/0014-5793(91)80152-S

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The 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).

【 授权许可】

Unknown