Beta-adrenergic receptor: stereospecific interaction of iodinated beta-blocking agent with high affinity site.
An iodine-labeled beta-adrenergic inhibitor ((125)l-hydroxybenzylpindolol) binds specifically to a site on turkey erythrocyte membranes. A series of beta-adrenergic agonists and inhibitors compete for this binding site, with apparent affinities paralleling biological effectiveness as activators or inhibitors of catecholaminestimulated adenylate cyclase. The activity of d-(+) agonists or inhibitors was 1 percent (or less) than that of the corresponding l-(-) isomers in competing for binding of the iodinated blocker as well as in affecting catecholamine-stimulated adenylate cyclase. 1-(-)-Norepinephrine was about one-tenth as active as l-(-)-isoproterenol in competing for the beta-blocking agent site. The stereospecificity of the interaction with the iodinated beta-blocking agent and the correspondence between affinity for site and biological potency of analogs suggested that this interaction is involved in function of the beta-adrenergic receptor.
D000262:Adenylyl Cyclases / Q000378:metabolism; D000319:Adrenergic beta-Antagonists / Q000378:metabolism*; D000818:Animals; D001554:Benzene; D001667:Binding, Competitive; D002395:Catecholamines / Q000378:metabolism / Q000494:pharmacology; D004912:Erythrocytes / Q000378:metabolism*; D066298:In Vitro Techniques; D007457:Iodine Radioisotopes; D007545:Isoproterenol / Q000494:pharmacology; D009638:Norepinephrine / Q000378:metabolism / Q000494:pharmacology; D010869:Pindolol / Q000031:analogs & derivatives / Q000378:metabolism; D011433:Propranolol / Q000378:metabolism; D011941:Receptors, Adrenergic; D013237:Stereoisomerism; D013268:Stimulation, Chemical; D013329:Structure-Activity Relationship; D014422:Turkeys
D000319:Adrenergic beta-Antagonists; D002395:Catecholamines; D007457:Iodine Radioisotopes; D011941:Receptors, Adrenergic; D011433:Propranolol; D010869:Pindolol; D000262:Adenylyl Cyclases; D001554:Benzene; D007545:Isoproterenol; D009638:Norepinephrine