title: Binding characteristics of the regulatory guanine nucleotide binding protein, and the activation of the enzyme adenylate cyclase, present in a bovine skeletal muscle membrane preparation.
abstract: The binding of [3H]GppNHp (beta, gamma-imido[8(-3)H] guanosine 5'-triphosphate) to membrane particles of a bovine skeletal muscle preparation, the m.trapezius, and the subsequent activation of adenylate cyclase in this preparation have been studied, both in the presence and absence of (-)-isoprenaline. Specific binding of [3H]GppNHp could be best explained on the assumption of a two-sites model, in which the binding sites displaying the higher affinity, appeared to be associated with the activation of adenylate cyclase, and are likely to include the regulatory guanine nucleotide binding protein (G/F or NS). The apparent excess of high affinity [3H]GppNHp binding sites over the number of beta-adrenoceptors in this preparation with respect to its possible physiological relevance is discussed.
mesh_terms: D000262:Adenylyl Cyclases / Q000032:analysis*; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism; D000242:Cyclic AMP / Q000096:biosynthesis; D004789:Enzyme Activation; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006165:Guanylyl Imidodiphosphate / Q000378:metabolism; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D007700:Kinetics; D009132:Muscles / Q000378:metabolism*; D011943:Receptors, Adrenergic, beta / Q000032:analysis; D014316:Tritium
chemical_list: D011943:Receptors, Adrenergic, beta; D014316:Tritium; D006165:Guanylyl Imidodiphosphate; D000242:Cyclic AMP; D019204:GTP-Binding Proteins; D000262:Adenylyl Cyclases; D007545:Isoproterenol