Demonstration of distinct agonist and antagonist conformations of the A1 adenosine receptor

Journal Article · Sat Aug 05 04:00:00 EDT 1989 · Journal of Biological Chemistry; (USA)

OSTI ID:5607793

Barrington, W W; Jacobson, K A; Stiles, G L ^[1]

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1. Duke Univ. Medical Center, Durham, NC (USA)

A1 adenosine receptor-binding subunits can be visualized using high affinity antagonist and agonist photoaffinity radioligands. In the present study, we examined whether agonists and antagonists bind to the same receptor-binding subunit and if agonists and antagonists induce different conformational states of the receptor in intact membranes. It was demonstrated that several agonist and antagonist photoaffinity receptor-binding subunit. When the agonist and antagonist photoaffinity labeled peptides were denatured and subjected to partial peptide map analysis using a two-dimensional gel electrophoresis system similar peptide fragments were generated from each specifically labeled protein. This suggests that both classes of ligand label and incorporate into the same binding subunit. Proteolytic digestions of agonist- and antagonist-occupied receptors in native intact membranes revealed distinct and different peptide fragments depending on whether the ligand was an agonist or an antagonist. Manipulation of incubation conditions to perturb ligand-receptor interactions alter the pattern of peptide fragments generated with each specific protease. These data suggest that agonist and antagonist photoaffinity probes interact with an incorporate into the same binding subunit but that agonist binding is associated with a unique and detectable receptor conformation.

• OSTI ID: 5607793
• Journal Information: Journal of Biological Chemistry; (USA), Journal Name: Journal of Biological Chemistry; (USA) Vol. 264:22; ISSN JBCHA; ISSN 0021-9258
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ADENOSINE
AFFINITY
ANIMALS
AZIDES
BIOCHEMICAL REACTION KINETICS
BODY
BRAIN
CATTLE
CELL CONSTITUENTS
CELL MEMBRANES
CENTRAL NERVOUS SYSTEM
DOMESTIC ANIMALS
ELECTROPHORESIS
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LIGANDS
MAMMALS
MEMBRANE PROTEINS
MEMBRANES
NERVOUS SYSTEM
NITROGEN COMPOUNDS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANS
PEPTIDES
PROTEIN STRUCTURE
PROTEINS
REACTION KINETICS
RECEPTORS
RIBOSIDES
RUMINANTS
TRACER TECHNIQUES
VERTEBRATES