Identification of the subunit structure of rat pineal adrenergic receptors by photoaffinity labeling.

Published

Journal Article

The adrenergic receptors of rat pineal gland were investigated using radiolabeled ligand binding and photoaffinity labeling techniques. 125I-2-[beta-(4-hydroxyphenyl)ethylaminomethyl]tetralone (125I-HEAT) and 125I-cyanopindolol (125I-CYP) labeled specific sites on rat pineal gland membranes with equilibrium dissociation constants (KD) of 48 (+/- 5) pM and 30 (+/- 5) pM, respectively. Binding site maxima were 481 (+/- 63) and 1,020 (+/- 85) fmol/mg protein. The sites labeled by 125I-HEAT had the pharmacological characteristics of alpha 1-adrenergic receptors. 125I-CYP-labeled beta-adrenergic receptors were characterized as a homogeneous population of beta 1-adrenergic receptors. The alpha 1- and beta 1-adrenergic receptors were covalently labeled with the specific photoaffinity probes 4-amino-6,7-dimethoxy-2-(4-[5-(4-azido-3-[125I]iodophenyl) pentanoyl]-1-piperazinyl) quinazoline (125I-APDQ) and 125I-p-azidobenzylcarazolol (125I-pABC). 125I-APDQ labeled an alpha 1-adrenergic receptor peptide of Mr = 74,000 (+/- 4,000), which was similar to peptides labeled in rat cerebral cortex, liver, and spleen. 125I-pABC labeled a single beta 1-adrenergic receptor peptide with a Mr = 42,000 (+/- 1,500), which differed from the 60-65,000 peptide commonly seen in mammalian tissues. Possible reasons for these differences are discussed.

Full Text

Duke Authors

Cited Authors

  • Dickinson, KE; Leeb-Lundberg, LM; Strasser, RH; Caron, MG; Lefkowitz, RJ

Published Date

  • April 1986

Published In

Volume / Issue

  • 46 / 4

Start / End Page

  • 1153 - 1160

PubMed ID

  • 3005506

Pubmed Central ID

  • 3005506

International Standard Serial Number (ISSN)

  • 0022-3042

Digital Object Identifier (DOI)

  • 10.1111/j.1471-4159.1986.tb00630.x

Language

  • eng

Conference Location

  • England