1
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Yang X, Michiels TJM, de Jong C, Soethoudt M, Dekker N, Gordon E, van der Stelt M, Heitman LH, van der Es D, IJzerman AP. An Affinity-Based Probe for the Human Adenosine A 2A Receptor. J Med Chem 2018; 61:7892-7901. [PMID: 30080404 PMCID: PMC6150691 DOI: 10.1021/acs.jmedchem.8b00860] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
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Using activity-based protein profiling
(ABPP), functional proteins
can be interrogated in their native environment. Despite their pharmaceutical
relevance, G protein-coupled receptors (GPCRs) have been difficult
to address through ABPP. In the current study, we took the prototypical
human adenosine A2A receptor (hA2AR) as the
starting point for the construction of a chemical toolbox allowing
two-step affinity-based labeling of GPCRs. First, we equipped an irreversibly
binding hA2AR ligand with a terminal alkyne to serve as
probe. We showed that our probe irreversibly and concentration-dependently
labeled purified hA2AR. Click-ligation with a sulfonated
cyanine-3 fluorophore allowed us to visualize the receptor on SDS-PAGE.
We further demonstrated that labeling of the purified hA2AR by our probe could be inhibited by selective antagonists. Lastly,
we showed successful labeling of the receptor in cell membranes overexpressing
hA2AR, making our probe a promising affinity-based tool
compound that sets the stage for the further development of probes
for GPCRs.
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Affiliation(s)
| | | | | | | | - Niek Dekker
- Discovery Sciences, IMED Biotech Unit , AstraZeneca , Gothenburg , Sweden
| | - Euan Gordon
- Discovery Sciences, IMED Biotech Unit , AstraZeneca , Gothenburg , Sweden
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2
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Soethoudt M, Stolze SC, Westphal MV, van Stralen L, Martella A, van Rooden EJ, Guba W, Varga ZV, Deng H, van Kasteren SI, Grether U, IJzerman AP, Pacher P, Carreira EM, Overkleeft HS, Ioan-Facsinay A, Heitman LH, van der Stelt M. Selective Photoaffinity Probe That Enables Assessment of Cannabinoid CB 2 Receptor Expression and Ligand Engagement in Human Cells. J Am Chem Soc 2018; 140:6067-6075. [PMID: 29420021 PMCID: PMC5958339 DOI: 10.1021/jacs.7b11281] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
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Chemical
tools and methods that report on G protein-coupled receptor
(GPCR) expression levels and receptor occupancy by small molecules
are highly desirable. We report the development of LEI121 as a photoreactive
probe to study the type 2 cannabinoid receptor (CB2R),
a promising GPCR to treat tissue injury and inflammatory diseases.
LEI121 is the first CB2R-selective bifunctional probe that
covalently captures CB2R upon photoactivation. An incorporated
alkyne serves as ligation handle for the introduction of reporter
groups. LEI121 enables target engagement studies and visualization
of endogenously expressed CB2R in HL-60 as well as primary
human immune cells using flow cytometry. Our findings show that strategically
functionalized probes allow monitoring of endogenous GPCR expression
and engagement in human cells using tandem photoclick chemistry and
hold promise as biomarkers in translational drug discovery.
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Affiliation(s)
| | | | - Matthias V Westphal
- Laboratorium für Organische Chemie , Eidgenössische Technische Hochschule Zürich , Vladimir-Prelog-Weg 3 , Zürich 8093 , Switzerland
| | - Luuk van Stralen
- Department of Rheumatology , Leiden University Medical Center , Albinusdreef 2 , Leiden 2333 ZA , The Netherlands
| | | | | | - Wolfgang Guba
- Roche Innovation Center Basel , F. Hoffmann-La Roche Ltd. , Grenzacherstrasse 124 , Basel 4070 , Switzerland
| | - Zoltan V Varga
- Laboratory of Cardiovascular Physiology and Tissue Injury , National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health , 5625 Fishers Lane , Rockville , Maryland 20852 , United States
| | | | | | - Uwe Grether
- Roche Innovation Center Basel , F. Hoffmann-La Roche Ltd. , Grenzacherstrasse 124 , Basel 4070 , Switzerland
| | | | - Pal Pacher
- Laboratory of Cardiovascular Physiology and Tissue Injury , National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health , 5625 Fishers Lane , Rockville , Maryland 20852 , United States
| | - Erick M Carreira
- Laboratorium für Organische Chemie , Eidgenössische Technische Hochschule Zürich , Vladimir-Prelog-Weg 3 , Zürich 8093 , Switzerland
| | | | - Andreea Ioan-Facsinay
- Department of Rheumatology , Leiden University Medical Center , Albinusdreef 2 , Leiden 2333 ZA , The Netherlands
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3
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Jörg M, Scammells PJ. Guidelines for the Synthesis of Small-Molecule Irreversible Probes Targeting G Protein-Coupled Receptors. ChemMedChem 2016; 11:1488-98. [PMID: 27347648 DOI: 10.1002/cmdc.201600066] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Revised: 06/07/2016] [Indexed: 02/03/2023]
Abstract
Irreversible probes have been proven to be useful pharmacological tools in the study of structural and functional features in drug receptor pharmacology. They have been demonstrated to be particularly valuable for the isolation and purification of receptors. Furthermore, irreversible probes are helpful tools for the identification and characterization of binding sites, thereby supporting the advancement of rational drug design. In this Minireview, we provide insight into universal strategies and guidelines to successfully synthesize irreversible probes that target G protein-coupled receptors (GPCRs). We provide an overview of commonly used chemoreactive and photoreactive groups, and make a comparison of their properties and potential applications. Furthermore, there is a particular focus on synthetic approaches to introduce these reactive groups based on commercially available reagents.
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Affiliation(s)
- Manuela Jörg
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, 3052, Victoria, Australia.
| | - Peter J Scammells
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, 3052, Victoria, Australia.
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4
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Grunbeck A, Sakmar TP. Probing G Protein-Coupled Receptor—Ligand Interactions with Targeted Photoactivatable Cross-Linkers. Biochemistry 2013; 52:8625-32. [DOI: 10.1021/bi401300y] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Amy Grunbeck
- Laboratory of Chemical Biology
and Signal Transduction, The Rockefeller University, 1230 York
Avenue, New York, New
York 10065, United States
| | - Thomas P. Sakmar
- Laboratory of Chemical Biology
and Signal Transduction, The Rockefeller University, 1230 York
Avenue, New York, New
York 10065, United States
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5
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Synthesis of a dual-labeled probe of dimethyl lithospermate B with photochemical and fluorescent properties. Molecules 2011; 16:9886-99. [PMID: 22124203 PMCID: PMC6264775 DOI: 10.3390/molecules16129886] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 11/18/2011] [Accepted: 11/22/2011] [Indexed: 01/09/2023] Open
Abstract
Dimethyl lithosermate B (DLB) is a highly potent natural antioxidant and antidiabetic polyphenol with unknown mode of action. To determine its cellular targets, a photochemical and fluorescent dimethyl lithopermate B probe was designed and efficiently synthesized. The dual-labeled chemical probe for biological application was evaluated by UV and fluorescence to determine its electrochemical absorption and emission properties. This probe could be valuable for investigating ligand-protein interactions and subcellular localization.
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6
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A diazirine-based photoaffinity etoposide probe for labeling topoisomerase II. Bioorg Med Chem 2009; 18:830-8. [PMID: 20006518 DOI: 10.1016/j.bmc.2009.11.048] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2009] [Revised: 11/13/2009] [Accepted: 11/21/2009] [Indexed: 11/23/2022]
Abstract
Etoposide is a widely used anticancer drug that targets topoisomerase II, an essential nuclear enzyme. However, despite the fact that it has been in use and studied for more than 30years the specific site on the enzyme to which it binds is unknown. In order to identify the etoposide binding site(s) on topoisomerase II, a diazirine-based photoaffinity etoposide analog probe has been synthesized and its photoreactivity and biological activities have been characterized. Upon UV irradiation, the diazirine probe rapidly produced a highly reactive carbene species that formed covalent adducts containing stable carbon-based bonds indicating that it should also be able to form stable covalent adducts with amino acid residues on topoisomerase II. The human leukemia K562 cell growth and topoisomerase II inhibitory properties of the diazirine probe suggest that it targets topoisomerase II in a manner similar to etoposide. The diazirine probe was also shown to act as a topoisomerase II poison through its ability to cause topoisomerase IIalpha-mediated double-strand cleavage of DNA. Additionally, the diazirine probe significantly increased protein-DNA covalent complex formation upon photoirradiation of diazirine probe-treated K562 cells, as compared to etoposide-treated cells. This result suggests that the photoactivated probe forms a covalent adduct with topoisomerase IIalpha. In conclusion, the present characterization of the chemical, biochemical, and biological properties of the newly synthesized diazirine-based photoaffinity etoposide analog indicates that use of a proteomics mass spectrometry approach will be a tractable strategy for future identification of the etoposide binding site(s) on topoisomerase II through covalent labeling of amino acid residues.
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7
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Abstract
Several methods have been developed to site-specifically incorporate photoreactive nucleotide analogs into DNA for the purpose of identifying the proteins and their domains that are in contact with particular regions of DNA. The synthesis of several deoxynucleotide analogs that have a photoreactive group tethered to the nucleotide base and the incorporation of these analogs into DNA are described. In a second approach, oligonucleotide with a photoreactive group attached to the phosphate backbone is chemically synthesized. The photoreactive oligonucleotide is then enzymatically incorporated into DNA by annealing it to a complementary DNA template and extending with DNA polymerase. Both approaches have been effectively used to map protein-DNA interactions in large multisubunit complexes such as the eukaryotic transcription or ATP-dependent chromatin remodeling complexes. Not only do these techniques map the binding sites of the various subunits in these complexes, but when coupled with peptide mapping also determine the protein domain that is in close proximity to the different DNA sites. The strength of these techniques is the ability to scan a large number of potential sites by making combinations of different DNA probes and is facilitated by using an immobilized DNA template for synthesis.
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8
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Tang C, Yang J, Liu MS. Progressive internalization of beta-adrenoceptors in the rat liver during different phases of sepsis. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1407:225-33. [PMID: 9748593 DOI: 10.1016/s0925-4439(98)00045-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Changes in the distribution of beta-adrenoceptors (beta ARs) in the plasma membrane and the light vesicle fractions of rat liver during different phases of sepsis were studied using [3H]dihydroalprenolol binding and photoaffinity labeling with [125I]iodocyanopindolol diazirine. Sepsis was induced by cecal ligation and puncture (CLP). Septic rats exhibit an initial hypermetabolic (hyperglycemic) phase (9 h after CLP; early sepsis) followed by a hypometabolic (hypoglycemic) phase (18 h after CLP; late sepsis). The radioligand studies show that in the plasma membranes, the density of beta ARs was decreased by 28-32% and 46-69% during the early and the late phases, respectively, of sepsis. In the light vesicles, the density of beta ARs was increased by 25-30% and 30-35% during the early and the late phases, respectively, of sepsis. The total number of the receptor binding sites (the sum of that in plasma membrane plus light vesicle) was decreased by 11-12% and 21-35% during the early and the late phases, respectively, of sepsis. These results indicate that beta ARs were progressively internalized from surface membranes to the intracellular sites and, furthermore, they were underexpressed in the rat liver during the progression of sepsis. Since hepatic glucose metabolism is known to be regulated by catecholamines, in part, through beta AR mediation, an internalization/underexpression of hepatic beta ARs may play a role in the altered glucose homeostasis during sepsis, particularly in the late hypometabolic phase of sepsis.
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Affiliation(s)
- C Tang
- Laboratory of Shock Research, Beijing Medical University, China
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9
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Jahns R, Siegmund C, Jahns V, Reiländer H, Maidhof A, Müller-Esterl W, Lohse MJ, Boege F. Probing human beta1- and beta2 -adrenoceptors with domain-specific fusion protein antibodies. Eur J Pharmacol 1997; 334:115-26. [PMID: 9346338 DOI: 10.1016/s0014-2999(97)80346-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In order to generate antibodies suitable for immunological studies on beta-adrenoceptors constitutively expressed at low levels in cells or tissues we have produced fusion proteins of the amino- and carboxy-terminus, and the second extracellular loop of the human beta1- or beta2-adrenoceptors with bacterial glutathione-S-transferase in E. coli. Rabbit antibodies raised against these fusion proteins strongly reacted with intact human beta1- or beta2-adrenoceptors in a subtype- and domain-specific manner. Antibodies directed against the second extracellular loop of the beta1-adrenoceptor reacted stronger with non-denatured receptors and decreased the affinity of the 3H-labelled antagonist (-)-4-(3-t-butylamino-2-hydroxypropoxy)-[5,7-3H]benzimidazol-2-one ([3H]CGP 12 177), indicating a specific interaction with the native receptor. In contrast, antibodies directed against carboxy- and amino-terminal receptor domains reacted strongly both with denatured and non-denatured receptors but did not interfere with binding of [3H]CGP 12 177. Affinity purified antibodies were used for detecting the beta1- or the beta2-adrenoceptor subtype heterologously produced in Sf9 cells by enzyme-linked immunosorbent assay, Western blotting, immunoprecipitation, and indirect immunofluorescence microscopy. Moreover, we could demonstrate that avidity, titers, and specificity of these antibodies were high enough for studying beta-adrenoceptors constitutively expressed in human A431 cells, where we observed a patched membrane distribution of the receptors.
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MESH Headings
- Animals
- Antibodies/immunology
- Antibody Specificity
- Blotting, Western
- Enzyme-Linked Immunosorbent Assay/methods
- Fluorescent Antibody Technique, Indirect
- Humans
- Precipitin Tests
- Rabbits
- Receptors, Adrenergic, beta-1/chemistry
- Receptors, Adrenergic, beta-1/immunology
- Receptors, Adrenergic, beta-2/chemistry
- Receptors, Adrenergic, beta-2/immunology
- Recombinant Fusion Proteins/chemistry
- Recombinant Fusion Proteins/immunology
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Affiliation(s)
- R Jahns
- Department of Pharmacology, University of Würzburg, Germany.
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10
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Jahns R, Siegmund C, Jahns V, Reiländer H, Maidhof A, Müller-Esterl W, Lohse MJ, Boege F. Probing human beta 1- and beta 2-adrenoceptors with domain-specific fusion protein antibodies. Eur J Pharmacol 1996; 316:111-21. [PMID: 8982658 DOI: 10.1016/s0014-2999(96)00654-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In order to generate antibodies suitable for immunological studies on beta-adrenoceptors constitutively expressed at low levels in cells or tissues we have produced fusion proteins of the amino- and carboxy-terminus, and the second extracellular loop of the human beta 1- or beta 2-adrenoceptors with bacterial glutathione-S-transferase in E. coli. Rabbit antibodies raised against these fusion proteins strongly reacted with intact human beta 1- or beta 2-adrenoceptors in a subtype- and domain-specific manner. Antibodies directed against the second extracellular loop of the beta 1-adrenoceptor reacted stronger with non-denatured receptors and decreased the affinity of the 3H-labelled antagonist (-)-4-(3-t-butylamino-2-hydroxypropoxy)-[5,7-3H]benzimidazol-2-one ([3H]CGP 12 177), indicating a specific interaction with the native receptor. In contrast, antibodies directed against carboxy- and amino-terminal receptor domains reacted strongly both with denatured and non-denatured receptors but did not interfere with binding of [3H]CGP 12 177. Affinity purified antibodies were used for detecting the beta 1- or the beta 2-adrenoceptor subtype heterologously produced in Sf9 cells by enzyme-linked immunosorbent assay, Western blotting, immunoprecipitation, and indirect immunofluorescence microscopy. Moreover, we could demonstrate that avidity, titers, and specificity of these antibodies were high enough for studying beta-adrenoceptors constitutively expressed in human A431 cells, where we observed a patched membrane distribution of the receptors.
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Affiliation(s)
- R Jahns
- Department of Pharmacology, University of Würzburg, Germany.
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11
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Freedman NJ, Liggett SB, Drachman DE, Pei G, Caron MG, Lefkowitz RJ. Phosphorylation and desensitization of the human beta 1-adrenergic receptor. Involvement of G protein-coupled receptor kinases and cAMP-dependent protein kinase. J Biol Chem 1995; 270:17953-61. [PMID: 7629102 DOI: 10.1074/jbc.270.30.17953] [Citation(s) in RCA: 249] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Persistent stimulation of the beta 1-adrenergic receptor (beta 1AR) engenders, within minutes, diminished responsiveness of the beta 1 AR/adenylyl cyclase signal transduction system. This desensitization remains incompletely defined mechanistically, however. We therefore tested the hypothesis that agonist-induced desensitization of the beta 1AR (like that of the related beta 2AR) involves phosphorylation of the receptor itself, by cAMP-dependent protein kinase (PKA) and the beta-adrenergic receptor kinase (beta ARK1) or other G protein-coupled receptor kinases (GRKs). Both Chinese hamster fibroblast and 293 cells demonstrate receptor-specific desensitization of the beta 1 AR within 3-5 min. Both cell types also express beta ARK1 and the associated inhibitory proteins beta-arrestin-1 and beta-arrestin-2, as assessed by immunoblotting. Agonist-induced beta 1AR desensitization in 293 cells correlates with a 2 +/- 0.3-fold increase in phosphorylation of the beta 1AR, determined by immunoprecipitation of the beta 1AR from cells metabolically labeled with 32P(i). This agonist-induced beta 1AR phosphorylation derives approximately equally from PKA and GRK activity, as judged by intact cell studies with kinase inhibitors or dominant negative beta ARK1 (K220R) mutant overexpression. Desensitization, likewise, is reduced by only approximately 50% when PKA is inhibited in the intact cells. Overexpression of rhodopsin kinase, beta ARK1, beta ARK2, or GRK5 significantly increases agonist-induced beta 1AR phosphorylation and concomitantly decreases agonist-stimulated cellular cAMP production (p < 0.05). Furthermore, purified beta ARK1, beta ARK2, and GRK5 all demonstrate agonist-dependent phosphorylation of the beta 1AR. Consistent with a GRK mechanism, receptor-specific desensitization of the beta 1AR was enhanced by overexpression of beta-arrestin-1 and -2 in transfected 293 cells. We conclude that rapid agonist-induced desensitization of the beta 1AR involves phosphorylation of the receptor by both PKA and at least beta ARK1 in intact cells. Like the beta 2AR, the beta 1AR appears to bind either beta-arrestin-1 or beta-arrestin-2 and to react with rhodopsin kinase, beta ARK1, beta ARK2, and GRK5.
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Affiliation(s)
- N J Freedman
- Howard Hughes Medical Institute, Department of Medicine (Cardiology), Duke University Medical Center, Durham, North Carolina 27710, USA
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12
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Luxembourg A. Anti-peptide monoclonal antibodies to the beta-adrenergic receptor: use in purification of beta receptor. Hybridoma (Larchmt) 1995; 14:261-4. [PMID: 7590789 DOI: 10.1089/hyb.1995.14.261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
This article describes a new immunopurification procedure based on monoclonal antibodies raised against peptides of the carboxy-terminal region of the turkey beta-adrenergic receptor. This procedure constitutes a significant purification step of recombinant beta-adrenergic receptors expressed in baculovirus-infected Sf9 cells, and allows the recovery of receptors able to activate Gs in phospholipid vesicles. Additionally, this procedure can be combined with affinity chromatography to yield nearly homogeneous receptor.
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Affiliation(s)
- A Luxembourg
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, USA
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13
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Noda K, Saad Y, Graham R, Karnik S. The high affinity state of the beta 2-adrenergic receptor requires unique interaction between conserved and non-conserved extracellular loop cysteines. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)37438-0] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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14
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Kleymann G, Boege F, Hahn M, Hampe W, Vasudevan S, Reiländer H. Human beta 2-adrenergic receptor produced in stably transformed insect cells is functionally coupled via endogenous GTP-binding protein to adenylyl cyclase. EUROPEAN JOURNAL OF BIOCHEMISTRY 1993; 213:797-804. [PMID: 8386637 DOI: 10.1111/j.1432-1033.1993.tb17822.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Spodoptera frugiperda insect cells (Sf9) containing the stably integrated human beta 2-adrenergic receptor gene under the control of the baculovirus IE1 promoter expressed up to 350,000 human receptors/cell. The number of receptors did not change with cell density or age of culture. The adrenergic receptors overexpressed in the insect cells were functional with respect to their ligand binding and signalling properties. Coupling of the receptors to endogenous GTP-binding proteins is demonstrated by hormone-dependent stimulation of GTPase and adenylyl cyclase activity in the transformed insect cells. Western-blot analysis revealed that the endogenous GTP-binding protein appears to be of the heterotrimeric type. Antibodies raised against the mammalian alpha subunit of stimulatory GTP-binding proteins cross-react with the insect alpha subunit of GTP-binding proteins, which also exhibits the same apparent molecular mass as its mammalian counterpart. The beta subunit of GTP-binding proteins from insect cells reacts with anti-peptide serum directed against the C-terminal amino acids of the mammalian beta subunit of GTP-binding proteins, but is about approximately 2 kDa larger than that of the beta subunit of GTP-binding proteins from bovine brain. Exposure of the transformed insect cells to L-isoproterenol rapidly induces uncoupling and internalization of 30% of the heterologously expressed receptors. In contrast to the situation in mammalian cells, prolonged exposure of the agonist (24 h) does not result in down regulation of the remaining 70% of the receptors.
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Affiliation(s)
- G Kleymann
- Max-Planck-Institut für Biophysik, Abt. Molekulare Membranbiologie, Frankfurt/M, Germany
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15
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Luxembourg A, Hekman M, Ross EM. Immunologic mapping of the amino- and carboxy-termini of the turkey erythrocyte beta-adrenergic receptor: selective proteolysis of both domains. FEBS Lett 1991; 283:155-8. [PMID: 1645295 DOI: 10.1016/0014-5793(91)80575-n] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Peptide-directed antibodies were used to map the N- and C-termini of the turkey erythrocyte beta-adrenergic receptor, the full length recombinant receptor expressed in Sf9 cells, and a mutant that terminates after residue 424 (T424). Both forms of the natural receptor (P40 and P50) were proteolytically clipped between residues 419 and 424. P40, but not P50, is also proteolyzed between residues 14 and 28. Truncation mutants, but not full length receptors, also display both large and small forms. The short form of T424 is formed by proteolysis after residue 14, but neither form is proteolyzed in the C-terminal region. The wild type recombinant receptor is not proteolyzed.
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Affiliation(s)
- A Luxembourg
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas 75235-9041
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16
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Parker EM, Kameyama K, Higashijima T, Ross EM. Reconstitutively active G protein-coupled receptors purified from baculovirus-infected insect cells. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)52467-4] [Citation(s) in RCA: 222] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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17
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A truncation mutation in the avian beta-adrenergic receptor causes agonist-induced internalization and GTP-sensitive agonist binding characteristic of mammalian receptors. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(18)38261-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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18
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Romano C, Williams WV, Fischberg DJ, Cocero N, Weiner DB, Greene MI, Molinoff PB. Subtype-selective immunoprecipitation of the beta 2-adrenergic receptor. J Neurochem 1989; 53:362-9. [PMID: 2545815 DOI: 10.1111/j.1471-4159.1989.tb07343.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Most antibodies known to interact with beta-adrenergic receptors do not exhibit subtype selectivity, nor do they provide quantitative immunoprecipitation. A monoclonal antibody, G27.1 raised against a synthetic peptide corresponding to the C-terminus of the beta 2-adrenergic receptor of hamster, is selective for the beta 2 subtype. G27.1 provides nearly quantitative immunoprecipitation of the beta 2-adrenergic receptor from hamster lung that has been photoaffinity-labeled and solubilized with sodium dodecyl sulfate. Immunoprecipitation is completely blocked by nanomolar concentrations of the immunizing peptide. This antibody interacts with beta 2-adrenergic receptors from three rodent species, but not with those from humans. When C6 glioma cells, which contain both beta 1- and beta 2-adrenergic receptors, are photoaffinity-labeled in the absence or presence of subtype-selective antagonists, subtype-selective photoaffinity-labeling results. G27.1 can immunoprecipitate beta 2-, but not beta 1-, adrenergic receptors from these cells. Similar results were obtained following subtype-selective photoaffinity-labeling of membranes from rat cerebellum and cerebral cortex. The beta-adrenergic receptors from C6 glioma cells and rat cerebral cortex exist as a mixture of two molecular weight species. These species differ in glycosylation, as shown by endoglycosidase F digestion of crude and immunoprecipitated receptors.
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Affiliation(s)
- C Romano
- Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia 19104-6084
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19
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Eshdat Y, Chapot MP, Strosberg AD. Chemical characterization of ligand binding site fragments from turkey beta-adrenergic receptor. FEBS Lett 1989; 246:166-70. [PMID: 2540034 DOI: 10.1016/0014-5793(89)80276-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Affinity-labeled beta-adrenergic receptor from turkey erythrocyte membranes was specifically cleaved near cysteine residues after S-cyanylation. Analysis of the labeled polypeptide fragments suggests that iodocyanopindolol diazirine reacted with an amino acid residue which is located in the non-glycosylated region containing the sixth and seventh transmembrane domains of the receptor. However, the possibility cannot be excluded that a second residue, located between the third and fifth transmembrane domains, was also labeled. Since treatment with either hydroxylamine or triethylamine resulted in removal of the affinity label from the protein, the present study suggests that aspartic or glutamic acid residues are present in the adrenergic-binding site which is located in the above-mentioned domains. The procedure for specific chemical cleavage of the affinity-labeled adrenergic receptor should also be useful for future structural and comparative studies of other adrenergic receptors.
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Affiliation(s)
- Y Eshdat
- Laboratoire de Biologie Moléculaire des Récepteurs, Centre National de la Recherche Scientifique, Université de Paris VII, France
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20
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Abstract
Binding of catecholamines to the beta-adrenergic receptor results in the activation of adenylate cyclase and the intracellular formation of adenosine 3',5'-monophosphate (cAMP). In the past 20 years the events that lead from hormone binding at the cell surface receptor site to the synthesis of cAMP at the inner layer of the membrane have been intensively studied. Signal transduction in this system involves the sequential interaction of the beta-adrenergic receptor with the guanine nucleotide-binding protein (Gs) and the adenylate cyclase catalyst (C). The mechanism of signal transduction from the receptor through Gs to C, as well as the role of the adenylate cyclase inhibitory G protein Gi, is discussed.
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Affiliation(s)
- A Levitzki
- Department of Biological Chemistry, Hebrew University of Jerusalem, Israel
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21
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Stadel JM, Rebar R, Crooke ST. Alkaline phosphatase relieves desensitization of adenylate cyclase-coupled beta-adrenergic receptors in avian erythrocyte membranes. Biochem J 1988; 252:771-6. [PMID: 2844155 PMCID: PMC1149214 DOI: 10.1042/bj2520771] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Desensitization of adenylate cyclase-coupled beta-adrenergic receptors in avian erythrocytes results in a 40-65% decrease in agonist-stimulated adenylate cyclase activity and correlates with increased phosphorylation of beta-adrenergic receptors. To assess the role of phosphorylation in desensitization, membranes from isoprenaline- and dibutyryl cyclic AMP-desensitized turkey erythrocytes were incubated with alkaline phosphatase for 30 min at 37 degrees C, pH 8.0. In both preparations alkaline phosphatase treatment significantly decreased desensitization of agonist-stimulated adenylate cyclase activity by 40-75% (P less than 0.05). Similar results were obtained after alkaline phosphatase treatment of membranes from isoprenaline- and dibutyryl cyclic AMP-desensitized duck erythrocytes. Moreover, alkaline phosphatase treatment of membranes from duck erythrocytes desensitized with 12-O-tetradecanoylphorbol 13-acetate returned agonist-stimulated adenylate cyclase activity to near control values. In all experiments, inclusion of 20 mM-sodium phosphate to inhibit alkaline phosphatase during treatment of membranes attenuated the enzyme's effect on agonist-stimulated adenylate cyclase activity. In addition, alkaline phosphatase treatment of membranes from control and isoprenaline-desensitized turkey erythrocytes increased the mobility of beta-adrenergic-receptor proteins, specifically photoaffinity-labelled with [125I]iodocyanopindolol-diazirine, on SDS/polyacrylamide-gel electrophoresis. The increased mobility of the beta-adrenergic-receptor proteins after alkaline phosphatase treatment of membranes was again inhibited by 20 mM-phosphate. These results provide additional evidence for a direct role for phosphorylation in desensitization of adenylate cyclase-coupled beta-adrenergic receptors in avian erythrocytes.
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Affiliation(s)
- J M Stadel
- Department of Molecular Pharmacology, Smith Kline and French Laboratories, Philadelphia, PA 19101
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22
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Wong SK, Slaughter C, Ruoho AE, Ross EM. The catecholamine binding site of the beta-adrenergic receptor is formed by juxtaposed membrane-spanning domains. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)68420-0] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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23
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Muzzin P, Colomb C, Giacobino JP, Venter JC, Fraser CM. Biochemical characterization of brown adipose tissue beta-adrenergic receptor. JOURNAL OF RECEPTOR RESEARCH 1988; 8:713-29. [PMID: 2839680 DOI: 10.3109/10799898809049021] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The beta-adrenergic receptor of rodent brown fat plays a key role in the control of energy dissipation by this tissue. The aim of the present study was to further characterize the biochemical properties of this receptor. The beta-receptor of rat interscapular brown adipose tissue plasma membranes was found to bind the beta-adrenergic antagonist [125I]cyanopindolol with a high affinity (KD 67 pM). The [125I]cyanopindolol receptor complex could be solubilized by digitonin and the isoelectric point of the solubilized receptor was found to be 5.8. Brown adipose tissue plasma membranes were labeled with the photoaffinity ligand [125I] cyanopindolol diazirine and labeled membrane proteins were separated by sodium dodecylsulfate polyacrylamide gel electrophoresis and analyzed by autoradiography. Autoradiograms revealed a peptide of 62 kDa whose labeling was stereoselectively displaced by alprenolol and isoproterenol. The beta 1-selective antagonist betaxolol was about 100 times more potent in displacing the labeling of this 62 kDa peptide than the beta 2-selective antagonist ICI 118,551. Based upon these data, it appears that the beta-receptor in brown adipose tissue is a beta 1 subtype with molecular weight of 62 kDa.
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Affiliation(s)
- P Muzzin
- Département de Biochimie médicale, Centre Médical Universitaire, Genève, Switzerland
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24
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Fraser CM, Chung FZ, Venter JC. Continuous high density expression of human beta 2-adrenergic receptors in a mouse cell line previously lacking beta-receptors. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)48099-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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25
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Dohlman HG, Bouvier M, Benovic JL, Caron MG, Lefkowitz RJ. The multiple membrane spanning topography of the beta 2-adrenergic receptor. Localization of the sites of binding, glycosylation, and regulatory phosphorylation by limited proteolysis. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)47935-5] [Citation(s) in RCA: 158] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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26
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Kaveri SV, Cervantes-Olivier P, Delavier-Klutchko C, Strosberg AD. Monoclonal antibodies directed against the human A431 beta 2-adrenergic receptor recognize two major polypeptide chains. EUROPEAN JOURNAL OF BIOCHEMISTRY 1987; 167:449-56. [PMID: 2820727 DOI: 10.1111/j.1432-1033.1987.tb13358.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A serum-albumin-alprenolol conjugate was used to isolate beta-adrenergic receptors from the human A431 cell lysates. Three monoclonal antibodies were obtained from BALB/c mice immunized with these receptors. These antibodies: BRK-1, BRK-2, BRK-3, were respectively of the IgM, IgG2a and IgG3 classes. All three antibodies recognized photoaffinity-labelled receptors, immunoprecipitated ligand-binding activity and identified the 65-kDa and 55-kDa polypeptides corresponding to the beta 2-adrenergic receptors of A431 cells. BRK-2 and BRK-3 recognized both beta 1 and beta 2-adrenergic receptors of several mammalian cells. All three antibodies visualized, by immunofluorescence, the beta 2-adrenergic receptors at the surface of A431 cells. The monoclonal antibodies are directed against the protein portion of the beta-adrenergic receptors since partial or complete removal of the carbohydrate moieties by treatment with endoglycosidase such as endo-F (endo-beta-N-acetylglucosaminidase F) and periodate oxidation did not affect the immunoreactivity. These antibodies will be of value to immunopurify the beta-adrenergic receptors.
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Affiliation(s)
- S V Kaveri
- Department of Biotechnology, Institut Pasteur, Paris
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27
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Mogre RM, Batliwala HF, Anjaneyulu PS, Lala AK. A new carbene based heterobifunctional reagent. Photochemical crosslinking of aldolase. FEBS Lett 1987; 221:408-14. [PMID: 3622779 DOI: 10.1016/0014-5793(87)80965-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The synthesis of a new photoactivatable heterobifunctional crosslinking reagent, the N-oxysuccinimide ester of 2-carboxy-9-diazofluorene, is described. The ability of the parent chromophore 2-carbomethoxy-9-diazofluorene to insert into cyclohexane and methanol has been established. The reagent has been linked to aldolase and the stoichiometry determined. Photolysis of the probe-linked aldolase indicated that photolysis was very rapid and that the photolysed product was constituted of crosslinked dimer, trimer and tetramer. Increase in concentration of probe linked to aldolase followed by photolysis gave rise to largely tetramer and higher oligomers of aldolase. The use of this carbene-based reagent vis a vis arylazide-based reagent for studying protein crosslinking is discussed.
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28
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Abstract
The beta-adrenergic receptors from various species have been extensively studied both at the pharmacologic and the structural level. Clinical observations may now be interpreted on the basis of mechanisms of interactions between catecholamines and their membrane receptors, regulation of these receptors by guanyl nucleotide binding proteins and stimulation of cyclic adenosine monophosphate production by adenylate cyclase.
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29
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Kashles O, Levitzki A. Characterization of the beta 2-adrenoceptor-dependent adenylate cyclase of A431 epidermoid carcinoma cells. Biochem Pharmacol 1987; 36:1531-8. [PMID: 3034291 DOI: 10.1016/0006-2952(87)90122-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
In this study we characterize the beta 2 adrenergic dependent adenylate cyclase system of epidermoid carcinoma cells (A431). We show that the cells synthesize up to 130,000 [125I]-cyanopindolol binding sites per cell when freshly plated, a value which decreased to 40,000-50,000 receptors/cell within 24 hr. Production of this high number of receptors can be strongly inhibited by actinomycin D. We confirm and extend the fact that these beta-adrenoceptors are of the beta 2-subtype, using selective ligands, photoaffinity labeling with [125I]CYP-diazirine identified two protein subunits: p59 and p72, the beta 2-adrenoceptor dependent adenylate cyclase desensitizes with half-life of 2.2 +/- 0.3 min whereas the loss of [125I]CYP binding from the cell surface requires longer exposure times to the agonist, phorbol-12-myristate-13-acetate (PMA) has no effect on the desensitization process nor does it have any effect on the modulation of beta-agonist affinity by guanyl nucleotides. Rather, PMA was found to stimulate adenylate cyclase activation by forskolin. We conclude that protein kinase C is probably not involved in the beta-adrenoceptor desensitization in this cell line.
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30
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31
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Fraser CM, Kerlavage AR, Mariani AP, Venter JC. Structural analysis of purified beta-adrenergic receptors. Proteins 1987; 2:34-41. [PMID: 3447167 DOI: 10.1002/prot.340020105] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We have characterized the structure of purified beta-adrenergic receptors by a combination of photoaffinity labeling, high performance liquid chromatography (HPLC)-tryptic mapping, CNBr fragmentation, target size analysis, and electron microscopy of purified receptor molecules. Guinea pig lung beta-adrenergic receptors purified by affinity chromatography, ion exchange chromatography, and HPLC size exclusion chromatography or photoaffinity labeled with [125]-iodocyanopindolol diazirine displayed mobilities on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) that corresponded to Mr = 68,000. Purified, radioiodinated guinea pig lung beta-receptors were subjected to complete trypsin digestion and subsequent reverse-phase HPLC analysis, which revealed nine peptides. Active site labeling and tryptic digestion of partially purified hamster lung beta-receptors produced one peptide, whereas CNBr digestion of the same material produced two labeled fragments, yielding information about the location of the active site within the primary sequence. Purified guinea pig lung receptors were examined with transmission electron microscopy. Electron micrographs revealed slightly asymmetric, rod-shaped structures with an average length of 13 nm and width of 3.4 nm. Many receptors were arranged as apparent dimeric structures. These findings confirm data obtained from target size analysis of guinea pig lung beta-receptors in situ which suggest that receptors may exist as oligomeric arrays in the native membrane. Taken together, these data provide information about putative functional domains of the beta-adrenergic receptor and its quaternary structure.
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Affiliation(s)
- C M Fraser
- Section of Receptor Biochemistry and Molecular Biology, National Institute of Neurological and Communicative Disorders and Stroke, Bethesda, Maryland 20892
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32
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Chapot MP, Cervantes P, Kaveri S, Durieu-Trautmann O, Delavier-Klutchko C, Emorine L, Couraud PO, Strosberg AD. Biochemical and immunochemical analysis of avian beta 1 and mammalian beta 2-adrenergic receptors. JOURNAL OF RECEPTOR RESEARCH 1987; 7:1-15. [PMID: 3040973 DOI: 10.3109/10799898709054976] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We have studied the molecular properties of avian beta 1-adrenergic receptor and human beta 2-adrenergic receptor. The turkey erythrocytes beta 1-receptor has been solubilized in active form by digitonin and has been purified to homogeneity by affinity chromatography followed by electroelution from polyacrylamide gel. The photoactivable ligand, iodocyanopindololdiazirine, labels specifically a major 45 kDa and minor 55 kDa polypeptide in turkey erythrocytes, whereas in A431, it labels two polypeptides of molecular weights 65 kDa and 55 kDa. Both types of receptors are N- and possibly O-glycosylated but the turkey beta 1 receptor has only complex carbohydrates whereas the human beta 2 receptor has in addition oligo mannosidic polysaccharidic moiety. Polyclonal and monoclonal antibodies were raised against the beta 1- and beta 2-adrenergic receptors. Polyclonal antibodies were found to mimic beta-adrenergic agonists by stimulating adenylate cyclase upon binding to the receptors. The monoclonal antibodies precipitated both intact and affinity labeled receptors which they also revealed on immunoblots.
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33
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Kerlavage AR, Fraser CM, Chung FZ, Venter JC. Molecular structure and evolution of adrenergic and cholinergic receptors. Proteins 1986; 1:287-301. [PMID: 3329731 DOI: 10.1002/prot.340010403] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- A R Kerlavage
- Section of Receptor Biochemistry and Molecular Biology, National Institute of Neurological and Communicative Disorders and Stroke, Bethesda, Maryland 20892
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34
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Jürss R, Hekman M, Helmreich EJ. Proteolysis-associated deglycosylation of beta 1-adrenergic receptor in turkey erythrocytes and membranes. Biochemistry 1985; 24:3349-54. [PMID: 2992582 DOI: 10.1021/bi00334a041] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A protease that can be inhibited by glutathione, dithiothreitol, and o-phenanthroline but not by ethylenediaminetetraacetic acid converts the 50-kilodalton beta-adrenergic receptor in turkey erythrocyte membranes to a 40-kDa polypeptide which retains the specific ligand binding site. This conversion is attenuated in intact erythrocytes. The large 50-kDa peptide contains N-linked, complex carbohydrates and is retained on wheat germ agglutinin-Sepharose. The 40-kDa product of proteolysis does not bind to the wheat germ agglutinin and can thus be separated from the 50-kDa polypeptide by lectin chromatography. However, the large difference in molecular weights of the two receptor peptides cannot be accounted for solely by the different extent of glycosylation.
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35
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Chorev M, Feigenbaum A, Keenan AK, Gilon C, Levitzki A. N-Bromoacetyl-amino-cyanopindolol: a highly potent beta-adrenergic affinity label blocks irreversibly a non-protein component tightly associated with the receptor. EUROPEAN JOURNAL OF BIOCHEMISTRY 1985; 146:9-14. [PMID: 2981685 DOI: 10.1111/j.1432-1033.1985.tb08613.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A new chemical affinity label for the beta-adrenergic receptor, based on the structure of pindolol, has been synthesized and iodinated with 125I. The compound, N-bromoacetylamino-cyanopindolol (BAM-CYP), has an apparent dissociation constant of 44 +/- 7 pM towards the turkey erythrocyte membranes. This compound blocks irreversibly both the ability of beta-adrenergic receptors to bind 125I-cyanopindolol and the ability of beta-receptors to activate adenylate cyclase in the presence of beta-agonists. Furthermore, the irreversible binding of BAM-CYP to half of the beta-receptor sites abolishes the ligand binding activity of all the sites. These findings suggest that the beta-receptor is oligomeric in its native state. Although 125I-BAM-CYP blocks irreversibly and specifically the beta-adrenergic receptor, it does so by labeling a non-protein component, most probably a water-soluble lipid. The labeling is stereospecific since it is prevented by l-propranolol and not by d-propranolol. It is suggested that this lipid is tightly associated with the receptor in close proximity to the binding site. It is also suggested that this water-soluble lipid fraction may prove crucial for the optimal interaction between the beta-adrenergic receptor and the components of adenylate cyclase.
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36
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37
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38
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Nassal M. 4-(1-Azi-2,2,2-trifluoroethyl)benzoic Acid, a Highly Photolabile Carbene Generating Label Readily Fixable to Biochemical Agents. ACTA ACUST UNITED AC 1983. [DOI: 10.1002/jlac.198319830907] [Citation(s) in RCA: 93] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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