Separation, identification and characterization of two structural domains of the mammalian. beta. /sub 2/-adrenergic receptor

Conference · Thu May 01 04:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5246717

Dohlman, H G; Caron, M G; Lefkowitz, R J

The ..beta..-adrenergic receptor is prototypic for hormone receptors that stimulate adenylate cyclase catalyzed production of cAMP in the cell. The receptor has recently been purified to homogeneity from mammalian tissues. Here the authors describe preliminary studies of the domain structure and function of the ..beta../sub 2/ subtype of the receptor purified from hamster lung. Native ..beta..-adrenergic receptor (M/sub r/ = 64,000) is cleaved by limited tryptic proteolysis into two fragments of M/sub r/ = 40,000 (40K) and M/sub r/ = 25,000 (25K). The functions of the two structural domains were determined. The 40K domain includes the binding site for the ..beta..-adrenergic receptor affinity ligand (/sup 125/I)-p-azidobenzylcarazolol. Treatment of the 40K domain with endo-..beta..-N-acetyl-glucosaminidase F results in a new M/sub r/ value of 24,000. Proteolysis of pure ..beta..-adrenergic receptor reconstituted into lipid vesicles results in dissociation of the 25K domain from the pelletable, membrane bound 40K domain. Thus, tryptic cleavage defines two distinct structural domains of hamster ..beta..-adrenergic receptor. The first domain, a M/sub r/ = 40,000 fragment, contains the sites of N-linked glycosylation, the hormone binding site, and the membrane spanning region. The second domain, with M/sub r/ = 25,000, is of unknown function and appears to be entirely extrinsic to the plasma membrane. Further studies are underway to determine the location of the sites of phosphorylation (involved in receptor desensitization) and effective coupling.

• Research Organization: Duke Univ. Medical Center, Durham, NC
• OSTI ID: 5246717
• Report Number(s): CONF-8606151-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:6
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AFFINITY
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BETA DECAY RADIOISOTOPES
BIOLOGICAL FUNCTIONS
BODY
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
CLEAVAGE
CRYSTAL STRUCTURE
DAYS LIVING RADIOISOTOPES
DECOMPOSITION
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
FUNCTIONS
HAMSTERS
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LIGANDS
LUNGS
MAMMALS
MEMBRANE PROTEINS
MICROSTRUCTURE
MOLECULAR STRUCTURE
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PROTEINS
PROTEOLYSIS
RADIOISOTOPES
RECEPTORS
RESPIRATORY SYSTEM
RODENTS
SYMPATHOMIMETICS
TRACER TECHNIQUES
VERTEBRATES