Covalent labeling of the beta-adrenergic ligand-binding site with para-(bromoacetamidyl)benzylcarazolol. A highly potent beta-adrenergic affinity label.

Published

Journal Article

para-(Bromoacetamidyl)benzylcarazolol (pBABC) was synthesized and found to be an extremely potent affinity label for beta-adrenergic receptors. Its interaction with mammalian (rabbit and hamster lung) and nonmammalian (turkey and frog erythrocyte) beta-adrenergic receptors was similar, displaying EC50 values of 400-900 pM for inhibiting 125I-cyanopindolol binding to these receptors. pBABC reduced the number of beta-adrenergic receptors in frog erythrocyte membranes, without any change in the affinity of the remaining sites for [125I]iodocyanopindolol. pBABC has been radioiodinated. As assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, this affinity probe specifically labeled the beta-adrenergic peptide of a purified preparation of hamster lung, with high efficiency (approximately 40%) and with a pharmacological specificity characteristic of an interaction at the beta 2-adrenergic receptor ligand-binding site. Comparison of the proteolyzed products derived from purified receptor labeled with [125I]pBABC and with the photoaffinity agent [125I]p-azidobenzylcarazolol suggested that covalent labeling of the beta-adrenergic receptor by these probes occurs at similar domains of the beta-adrenergic receptor. Because of the much higher level of incorporation of this affinity probe as opposed to photosensitive probes, pBABC should prove to be a useful tool for structural studies of purified beta-adrenergic receptors.

Full Text

Duke Authors

Cited Authors

  • Dickinson, KE; Heald, SL; Jeffs, PW; Lefkowitz, RJ; Caron, MG

Published Date

  • May 1, 1985

Published In

Volume / Issue

  • 27 / 5

Start / End Page

  • 499 - 506

PubMed ID

  • 2985948

Pubmed Central ID

  • 2985948

International Standard Serial Number (ISSN)

  • 0026-895X

Language

  • eng

Conference Location

  • United States