Photoaffinity labeling of mammalian α1-adrenergic receptors. Identification of the ligand binding subunit with a high affinity radioiodinated probe
(1984) In Journal of Biological Chemistry 259(4). p.2579-2587- Abstract
We have synthesized and characterized a novel high affinity radioiodinated α1-adrenergic receptor photoaffinity probe, 4-amino-6,7-dimethoxy-2-[4-[5-(4-azido-3-[125I]iodophenyl)pentanoyl]-1-p iperazinyl] quinazoline. In the absence of light, this ligand binds with high affinity (K(D) = 130 pM) in a reversible and saturable manner to sites in rat hepatic plasma membranes. The binding is stereoselective and competitively inhibited by adrenergic agonists and antagonists with an α1-adrenergic specificity. Upon photolysis, this ligand incorporates irreversibly into plasma membranes prepared from several mammalian tissues including rat liver, rat, guinea pig, and rabbit spleen, rabbit lung, and rabbit aorta... (More)
We have synthesized and characterized a novel high affinity radioiodinated α1-adrenergic receptor photoaffinity probe, 4-amino-6,7-dimethoxy-2-[4-[5-(4-azido-3-[125I]iodophenyl)pentanoyl]-1-p iperazinyl] quinazoline. In the absence of light, this ligand binds with high affinity (K(D) = 130 pM) in a reversible and saturable manner to sites in rat hepatic plasma membranes. The binding is stereoselective and competitively inhibited by adrenergic agonists and antagonists with an α1-adrenergic specificity. Upon photolysis, this ligand incorporates irreversibly into plasma membranes prepared from several mammalian tissues including rat liver, rat, guinea pig, and rabbit spleen, rabbit lung, and rabbit aorta vascular smooth muscle cells, also with typical α1-adrenergic specificity. Autoradiograms of such membrane samples subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis reveal a major specifically labeled polypeptide at M(r) = 78,000-85,000, depending on the tissue used, in addition to some lower molecular weight peptides. Protease inhibitors, in particular EDTA, a metalloprotease inhibitor, dramatically increases the predominance of the M(r) = 78,000-85,000 polypeptide while attenuating the labeling of the lower molecular weight bands. This new high affinity radioiodinated photoaffinity probe should be of great value for the molecular characterization of the α1-adrenergic receptor.
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- author
- Leeb Lundberg, L. M.F. LU ; Dickinson, K. E.J. and Heald, S. L.
- publishing date
- 1984-01-01
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Biological Chemistry
- volume
- 259
- issue
- 4
- pages
- 2579 - 2587
- publisher
- American Society for Biochemistry and Molecular Biology
- external identifiers
-
- scopus:0021325760
- pmid:6321475
- ISSN
- 0021-9258
- language
- English
- LU publication?
- no
- id
- b51c41f4-9089-44d8-bd3b-baed76525dd8
- date added to LUP
- 2019-06-04 14:49:49
- date last changed
- 2025-04-04 14:42:03
@article{b51c41f4-9089-44d8-bd3b-baed76525dd8,
abstract = {{<p>We have synthesized and characterized a novel high affinity radioiodinated α<sub>1</sub>-adrenergic receptor photoaffinity probe, 4-amino-6,7-dimethoxy-2-[4-[5-(4-azido-3-[<sup>125</sup>I]iodophenyl)pentanoyl]-1-p iperazinyl] quinazoline. In the absence of light, this ligand binds with high affinity (K(D) = 130 pM) in a reversible and saturable manner to sites in rat hepatic plasma membranes. The binding is stereoselective and competitively inhibited by adrenergic agonists and antagonists with an α<sub>1</sub>-adrenergic specificity. Upon photolysis, this ligand incorporates irreversibly into plasma membranes prepared from several mammalian tissues including rat liver, rat, guinea pig, and rabbit spleen, rabbit lung, and rabbit aorta vascular smooth muscle cells, also with typical α<sub>1</sub>-adrenergic specificity. Autoradiograms of such membrane samples subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis reveal a major specifically labeled polypeptide at M(r) = 78,000-85,000, depending on the tissue used, in addition to some lower molecular weight peptides. Protease inhibitors, in particular EDTA, a metalloprotease inhibitor, dramatically increases the predominance of the M(r) = 78,000-85,000 polypeptide while attenuating the labeling of the lower molecular weight bands. This new high affinity radioiodinated photoaffinity probe should be of great value for the molecular characterization of the α<sub>1</sub>-adrenergic receptor.</p>}},
author = {{Leeb Lundberg, L. M.F. and Dickinson, K. E.J. and Heald, S. L.}},
issn = {{0021-9258}},
language = {{eng}},
month = {{01}},
number = {{4}},
pages = {{2579--2587}},
publisher = {{American Society for Biochemistry and Molecular Biology}},
series = {{Journal of Biological Chemistry}},
title = {{Photoaffinity labeling of mammalian α<sub>1</sub>-adrenergic receptors. Identification of the ligand binding subunit with a high affinity radioiodinated probe}},
volume = {{259}},
year = {{1984}},
}