Abstract:
:Exposure of receptor-rich membrane fragments from Torpedo marmorata to carbamylcholine causes a slow (half-time of 5--10 min) and reversible change of properties of the cholinergic receptor protein manifested by a decrease of the initial rate of Naja nigricollis alpha-[3H]toxin binding in the presence of carbamylcholine. This change corresponds to a 5- to 20-fold increase of affinity for carbamylcholine. Other agonists, acetylcholine, phenyltrimethylammonium, show the same effect but not the antagonists d-tubocurarine and flaxedil. Decamethonium and hexamethonium show little, if any, agonistic effect in vitro on the same membrane fragments but cause the affinity change. This regulatory property can be lost after aging of the preparation of membrane fragments. Since the affinity increase progresses with a similar time course as the decrease of amplitude of the permeability response consecutive to agonist preincubation, it is proposed that, in the membrane at rest, the receptor protein is present under a state of low affinity for agonists and that the reversible stabilization by the agonists of a high affinity state corresponds to the "pharmacological desensitization" of the system as predicted by one of the models of Katz and Thesleff.
journal_name
Proc Natl Acad Sci U S Aauthors
Weber M,David-Pfeuty T,Changeux JPdoi
10.1073/pnas.72.9.3443keywords:
subject
Has Abstractpub_date
1975-09-01 00:00:00pages
3443-7issue
9eissn
0027-8424issn
1091-6490journal_volume
72pub_type
杂志文章abstract::The human beta(2)-adrenergic receptor gene has multiple single-nucleotide polymorphisms (SNPs), but the relevance of chromosomally phased SNPs (haplotypes) is not known. The phylogeny and the in vitro and in vivo consequences of variations in the 5' upstream and ORF were delineated in a multiethnic reference populatio...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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doi:10.1073/pnas.97.19.10483
更新日期:2000-09-12 00:00:00
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更新日期:2015-01-06 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:1977-11-01 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2003-04-15 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:1969-07-01 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:1994-05-24 00:00:00
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更新日期:1982-08-01 00:00:00