Interactions of. beta. -adrenergic receptors with guanine nucleotide-binding proteins

Thesis/Dissertation · Tue Jan 01 00:00:00 EST 1985

OSTI ID:6709443

Abramson, S N

The properties of ..beta..-adrenergic receptors were investigated with radioligand binding assays using the agonists (/sup 3/H)hydroxybenzyl-isoproterenol (/sup 3/H-HBI) and (/sup 3/H)epinephrine (/sup 3/H-EPI), and the antagonist (/sup 125/I)iodopindolol (/sup 125/I-IPIN). Membranes prepared from L6 myoblasts bound (/sup 3/H)HBI, (/sup 3/H)EPI, and (/sup 125/I)IPIN with high affinity and Scatchard plots revealed densities of 222 +/- 23, 111 +/- 7, and 325 +/- 37 fmol/mg of protein, respectively. Binding of (/sup 3/H)HBI and (/sup 3/H)EPI was inhibited allosterically by guanine nucleotides. Membranes prepared from wild-type S49 lymphoma cells bound (/sup 3/H)HBI and (/sup 125/I)IPIN with high affinity and Scatchard plots revealed densities of 48.9 +/- 7.1 and 196 +/- 29 fmol/mg of protein, respectively. Binding of (/sup 3/H)HBI was inhibited allosterically by GTP. Similar results were obtained with membranes prepared from the adenylate cyclase deficient variant of S49 lymphoma cells (cyc-), which does not contain a functional stimulatory guanine nucleotide-binding protein (N/sub s/), but does contain a functional inhibitory guanine nucleotide-binding protein (N/sub i/). Binding of (/sup 3/H)HBI to membranes prepared from cyc- S49 cells was inhibited by pretreatment of cells with pertussis toxin. These results suggest that ..beta..-adrenergic receptors on membranes prepared from cyc- S49 cells interact with N/sub i/ to form a ternary complex composed of agonist, receptor, and N/sub i/.

• Research Organization: Colorado Univ., Denver (USA). Health Sciences Center
• OSTI ID: 6709443
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
NUCLEOTIDES
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CELL MEMBRANES
GUANINE
IODINE 125
LABELLED COMPOUNDS
LYMPHOMAS
MYOBLASTS
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INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MEMBRANE PROTEINS
MEMBRANES
MUSCLES
NEOPLASMS
NUCLEI
ODD-EVEN NUCLEI
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ORGANIC NITROGEN COMPOUNDS
PURINES
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TRACER TECHNIQUES
550301* - Cytology- Tracer Techniques