Rapid binding of guanosine 5'-0-(3-thiotriphosphate) to an apparent complex of .beta.-adrenergic receptor and the GTP-binding regulatory protein Gs

28 June 1988

journal article
research article
Published by American Chemical Society (ACS) in Biochemistry

Vol. 27 (13) , 4888-4893
https://doi.org/10.1021/bi00413a045

Abstract

When reconstituted phospholipid vesicles that contain purified .beta.-adrenergic receptors and the GTP-binding regulatory protein Gs were preincubated with agonist before the addition of guanosine 5''-O-(3-thiotriphosphate) (GTP.gamma.-S), the typical receptor-stimulated GTP.gamma.S binding reaction was preceded by an even more rapid burst of GTP.gamma.S binding. This burst was studied in detail at 0.degree. C. The rate of the burst was second order in nucleotide and Gs [Kassoc .apprx. 2 .times. 107 (M .cntdot. min)-1], consistent with diffusion-controlled binding. The magnitude of the burst was always less than the number of receptors present and was roughly linear with receptor number when similarly prepared vesicles were compared. There was no obvious quantitative correlation between the burst and the amount of Gs. The species that gave rise to the burst formed with t1/2 .apprx. 15 min at 0.degree. C in the presence of agonist and decayed by .apprx. 3 min upon addition of antagonist or detergent. Formation and decay of this species was much faster at 30.degree. C.The data suggest that a complex of agonist, receptor, and Gs that is primed for the rapid binding of guanine nucleotide can form and be analyzed in reconstituted vesicles.

This publication has 21 references indexed in Scilit:

Reconstitution of catecholamine-stimulated binding of guanosine 5'-O-(3-thiotriphosphate) to the stimulatory GTP-binding protein of adenylate cyclase
Biochemistry, 1984
Catecholamine-stimulated guanosine 5'-O-(3-thiotriphosphate) binding to the stimulatory GTP-binding protein of adenylate cyclase: kinetic analysis in reconstituted phospholipid vesicles
Biochemistry, 1984
Mammalian .beta.2-adrenergic receptor: reconstitution of functional interactions between pure receptor and pure stimulatory nucleotide binding protein of the adenylate cyclase system
Biochemistry, 1984
(±)[125Iodo]cyanopindolol, a new ligand for β-adrenoceptors: Identification and quantitation of subclasses of β-adrenoceptors in guinea pig
Naunyn-Schmiedebergs Archiv für experimentelle Pathologie und Pharmakologie, 1981
Agonist-promoted coupling of the beta-adrenergic receptor with the guanine nucleotide regulatory protein of the adenylate cyclase system.
Proceedings of the National Academy of Sciences, 1980
Fundamental difference between the molecular interactions of agonists and antagonists with the β-adrenergic receptor
Nature, 1979
Adenylate cyclase activation by the .beta.-adrenergic receptors as a diffusion-controlled process
Biochemistry, 1979
Mechanism of adenylate cyclase activation through the beta-adrenergic receptor: catecholamine-induced displacement of bound GDP by GTP.
Proceedings of the National Academy of Sciences, 1978
Solubilization and separation of the glucagon receptor and adenylate cyclase in guanine nucleotide-sensitive states.
Journal of Biological Chemistry, 1977
AGONIST-SPECIFIC EFFECT OF GUANINE NUCLEOTIDES ON BINDING TO BETA-ADRENERGIC-RECEPTOR
1976