期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1980
卷号：77
期号：7
页码：3801-3805
DOI：10.1073/pnas.77.7.3801
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：beta 1-Adrenergic receptors from turkey erythrocyte membranes have been identified by specific binding of the radiolabeled antagonist (-)-[3H]dihydroalprenolol. These receptors are inactivated by the alkylating agent N-ethylmaleimide when occupied by beta-adrenergic agonists but not when occupied by antagonists or when unoccupied. A time-dependent decrease of the number of receptor sites is observed. Inactivation affects 45-60% of the sites, regardless of the agonist or N-ethylmaleimide concentration. The guanine nucleotides GTP and 5'-guanylyl imidodiphosphate effectively protect the receptors against agonist-mediated inactivation by N-ethylmaleimide. Protection by ATP necessitates a 100-fold higher concentration; 10 mM NaF is ineffective. The guanine nucleotide effect is reversible and occurs via interaction with N-ethylmaleimide-insensitive sites. These observations establish that guanine nucleotide sites interact with and caused structural modification of the agonist-occupied beta-adrenergic receptors in turkey erythrocyte membranes.
