1
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Vogt H, Shinkwin P, Huber ME, Staffen N, Hübner H, Gmeiner P, Schiedel M, Weikert D. Development of a Fluorescent Ligand for the Intracellular Allosteric Binding Site of the Neurotensin Receptor 1. ACS Pharmacol Transl Sci 2024; 7:1533-1545. [PMID: 38751637 PMCID: PMC11092115 DOI: 10.1021/acsptsci.4c00086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 04/02/2024] [Accepted: 04/09/2024] [Indexed: 05/18/2024]
Abstract
The membrane protein family of G protein-coupled receptors (GPCRs) represents a major class of drug targets. Over the last years, the presence of additional intracellular binding sites besides the canonical orthosteric binding pocket has been demonstrated for an increasing number of GPCRs. Allosteric modulators harnessing these pockets may represent valuable alternatives when targeting the orthosteric pocket is not successful for drug development. Starting from SBI-553, a recently discovered intracellular allosteric modulator for neurotensin receptor subtype 1 (NTSR1), we developed the fluorescent molecular probe 14. Compound 14 binds to NTSR1 with an affinity of 0.68 μM in the presence of the agonist NT(8-13). NanoBRET-based ligand binding assays with 14 were established to derive the affinity and structure-activity relationships for allosteric NTSR1 modulators in a direct and nonisotopic manner, thereby facilitating the search for and optimization of novel allosteric NTSR1 ligands. As a consequence of cooperativity between the ligands binding to the allosteric and orthosteric pocket, compound 14 can also be used to investigate orthosteric NTSR1 agonists and antagonists. Moreover, employing 14 as a probe in a drug library screening, we identified novel chemotypes as binders for the intracellular allosteric SBI-553 binding pocket of NTSR1 with single-digit micromolar affinity. These hits may serve as interesting starting points for the development of novel intracellular allosteric ligands for NTSR1 as a highly interesting yet unexploited drug target in the fields of pain and addiction disorder therapy.
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Affiliation(s)
- Hannah Vogt
- Department
of Chemistry and Pharmacy, Medicinal Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Nikolaus-Fiebiger-Straße 10, 91058 Erlangen, Germany
| | - Patrick Shinkwin
- Department
of Chemistry and Pharmacy, Medicinal Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Nikolaus-Fiebiger-Straße 10, 91058 Erlangen, Germany
| | - Max E. Huber
- Department
of Chemistry and Pharmacy, Medicinal Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Nikolaus-Fiebiger-Straße 10, 91058 Erlangen, Germany
| | - Nico Staffen
- Department
of Chemistry and Pharmacy, Medicinal Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Nikolaus-Fiebiger-Straße 10, 91058 Erlangen, Germany
| | - Harald Hübner
- Department
of Chemistry and Pharmacy, Medicinal Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Nikolaus-Fiebiger-Straße 10, 91058 Erlangen, Germany
| | - Peter Gmeiner
- Department
of Chemistry and Pharmacy, Medicinal Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Nikolaus-Fiebiger-Straße 10, 91058 Erlangen, Germany
- FAU
NeW − Research Center New Bioactive Compounds, Friedrich-Alexander-Universität Erlangen-Nürnberg, Nikolaus-Fiebiger-Str. 10, 91058 Erlangen, Germany
| | - Matthias Schiedel
- Department
of Chemistry and Pharmacy, Medicinal Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Nikolaus-Fiebiger-Straße 10, 91058 Erlangen, Germany
- Institute
of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Beethovenstraße 55, 38106 Braunschweig, Germany
| | - Dorothee Weikert
- Department
of Chemistry and Pharmacy, Medicinal Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Nikolaus-Fiebiger-Straße 10, 91058 Erlangen, Germany
- FAU
NeW − Research Center New Bioactive Compounds, Friedrich-Alexander-Universität Erlangen-Nürnberg, Nikolaus-Fiebiger-Str. 10, 91058 Erlangen, Germany
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2
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Gleixner J, Kopanchuk S, Grätz L, Tahk MJ, Laasfeld T, Veikšina S, Höring C, Gattor AO, Humphrys LJ, Müller C, Archipowa N, Köckenberger J, Heinrich MR, Kutta RJ, Rinken A, Keller M. Illuminating Neuropeptide Y Y 4 Receptor Binding: Fluorescent Cyclic Peptides with Subnanomolar Binding Affinity as Novel Molecular Tools. ACS Pharmacol Transl Sci 2024; 7:1142-1168. [PMID: 38633582 PMCID: PMC11019746 DOI: 10.1021/acsptsci.4c00013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 02/20/2024] [Accepted: 02/29/2024] [Indexed: 04/19/2024]
Abstract
The neuropeptide Y (NPY) Y4 receptor (Y4R), a member of the family of NPY receptors, is physiologically activated by the linear 36-amino acid peptide pancreatic polypeptide (PP). The Y4R is involved in the regulation of various biological processes, most importantly pancreatic secretion, gastrointestinal motility, and regulation of food intake. So far, Y4R binding affinities have been mostly studied in radiochemical binding assays. Except for a few fluorescently labeled PP derivatives, fluorescence-tagged Y4R ligands with high affinity have not been reported. Here, we introduce differently fluorescence-labeled (Sulfo-Cy5, Cy3B, Py-1, Py-5) Y4R ligands derived from recently reported cyclic hexapeptides showing picomolar Y4R binding affinity. With pKi values of 9.22-9.71 (radioligand competition binding assay), all fluorescent ligands (16-19) showed excellent Y4R affinity. Y4R saturation binding, binding kinetics, and competition binding with reference ligands were studied using different fluorescence-based methods: flow cytometry (Sulfo-Cy5, Cy3B, and Py-1 label), fluorescence anisotropy (Cy3B label), and NanoBRET (Cy3B label) binding assays. These experiments confirmed the high binding affinity to Y4R (equilibrium pKd: 9.02-9.9) and proved the applicability of the probes for fluorescence-based Y4R competition binding studies and imaging techniques such as single-receptor molecule tracking.
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Affiliation(s)
- Jakob Gleixner
- Institute
of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93040 Regensburg, Germany
| | - Sergei Kopanchuk
- Institute
of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Lukas Grätz
- Institute
of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93040 Regensburg, Germany
| | - Maris-Johanna Tahk
- Institute
of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Tõnis Laasfeld
- Institute
of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Santa Veikšina
- Institute
of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Carina Höring
- Institute
of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93040 Regensburg, Germany
| | - Albert O. Gattor
- Institute
of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93040 Regensburg, Germany
| | - Laura J. Humphrys
- Institute
of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93040 Regensburg, Germany
| | - Christoph Müller
- Institute
of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93040 Regensburg, Germany
| | - Nataliya Archipowa
- Institute
of Biophysics and Physical Biochemistry, Faculty of Biology and Preclinical
Medicine, University of Regensburg, Universitätsstraße 31, D-93040 Regensburg, Germany
| | - Johannes Köckenberger
- Department
of Chemistry and Pharmacy, Molecular and Clinical Pharmacy, Friedrich-Alexander-University Erlangen-Nürnberg, Nikolaus-Fiebiger-Straße 10, D-91058 Erlangen, Germany
| | - Markus R. Heinrich
- Department
of Chemistry and Pharmacy, Molecular and Clinical Pharmacy, Friedrich-Alexander-University Erlangen-Nürnberg, Nikolaus-Fiebiger-Straße 10, D-91058 Erlangen, Germany
| | - Roger Jan Kutta
- Institute
of Physical and Theoretical Chemistry, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Ago Rinken
- Institute
of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Max Keller
- Institute
of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93040 Regensburg, Germany
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3
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Mitchell-White JI, Briggs DA, Mistry SJ, Mbiwan HA, Kellam B, Holliday ND, Briddon SJ, Kerr ID. A time-resolved Förster resonance energy transfer assay to investigate drug and inhibitor binding to ABCG2. Arch Biochem Biophys 2024; 753:109915. [PMID: 38307314 DOI: 10.1016/j.abb.2024.109915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/21/2023] [Accepted: 01/17/2024] [Indexed: 02/04/2024]
Abstract
The human ATP-binding cassette (ABC) transporter, ABCG2, is responsible for multidrug resistance in some tumours. Detailed knowledge of its activity is crucial for understanding drug transport and resistance in cancer, and has implications for wider pharmacokinetics. The binding of substrates and inhibitors is a key stage in the transport cycle of ABCG2. Here, we describe a novel binding assay using a high affinity fluorescent inhibitor based on Ko143 and time-resolved Förster resonance energy transfer (TR-FRET) to measure saturation binding to ABCG2. This binding is displaced by Ko143 and other known ABCG2 ligands, and is sensitive to the addition of AMP-PNP, a non-hydrolysable ATP analogue. This assay complements the arsenal of methods for determining drug:ABCG2 interactions and has the possibility of being adaptable for other multidrug pumps.
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Affiliation(s)
- James I Mitchell-White
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK; Centre of Membrane Proteins and Receptors, Universities of Birmingham and Nottingham, The Midlands, UK.
| | - Deborah A Briggs
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - Sarah J Mistry
- School of Pharmacy, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Hannah A Mbiwan
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK; School of Pharmacy, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Barrie Kellam
- School of Pharmacy, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Nicholas D Holliday
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - Stephen J Briddon
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK; Centre of Membrane Proteins and Receptors, Universities of Birmingham and Nottingham, The Midlands, UK
| | - Ian D Kerr
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK.
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4
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Nagl M, Mönnich D, Rosier N, Schihada H, Sirbu A, Konar N, Reyes-Resina I, Navarro G, Franco R, Kolb P, Annibale P, Pockes S. Fluorescent Tools for the Imaging of Dopamine D 2 -Like Receptors. Chembiochem 2024; 25:e202300659. [PMID: 37942961 DOI: 10.1002/cbic.202300659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 11/08/2023] [Accepted: 11/09/2023] [Indexed: 11/10/2023]
Abstract
The family of dopamine D2 -like receptors represents an interesting target for a variety of neurological diseases, e. g. Parkinson's disease (PD), addiction, or schizophrenia. In this study we describe the synthesis of a new set of fluorescent ligands as tools for visualization of dopamine D2 -like receptors. Pharmacological characterization in radioligand binding studies identified UR-MN212 (20) as a high-affinity ligand for D2 -like receptors (pKi (D2long R)=8.24, pKi (D3 R)=8.58, pKi (D4 R)=7.78) with decent selectivity towards D1 -like receptors. Compound 20 is a neutral antagonist in a Go1 activation assay at the D2long R, D3 R, and D4 R, which is an important feature for studies using whole cells. The neutral antagonist 20, equipped with a 5-TAMRA dye, displayed rapid association to the D2long R in binding studies using confocal microscopy demonstrating its suitability for fluorescence microscopy. Furthermore, in molecular brightness studies, the ligand's binding affinity could be determined in a single-digit nanomolar range that was in good agreement with radioligand binding data. Therefore, the fluorescent compound can be used for quantitative characterization of native D2 -like receptors in a broad variety of experimental setups.
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Affiliation(s)
- Martin Nagl
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053, Regensburg, Germany
| | - Denise Mönnich
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053, Regensburg, Germany
| | - Niklas Rosier
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053, Regensburg, Germany
| | - Hannes Schihada
- Department of Pharmaceutical Chemistry, University of Marburg, Marbacher Weg 6, 35037, Marburg, Germany
| | - Alexei Sirbu
- Max Delbrück Center for Molecular Medicine, Berlin, 13125, Germany
| | - Nergis Konar
- Max Delbrück Center for Molecular Medicine, Berlin, 13125, Germany
| | - Irene Reyes-Resina
- CiberNed, Network Center for Neurodegenerative diseases, National Spanish Health Institute Carlos III, Madrid, Spain
- Department Biochemistry and Physiology, School of Pharmacy and Food Sciences, Universitat de Barcelona, Barcelona, Spain
| | - Gemma Navarro
- CiberNed, Network Center for Neurodegenerative diseases, National Spanish Health Institute Carlos III, Madrid, Spain
- Department Biochemistry and Physiology, School of Pharmacy and Food Sciences, Universitat de Barcelona, Barcelona, Spain
| | - Rafael Franco
- CiberNed, Network Center for Neurodegenerative diseases, National Spanish Health Institute Carlos III, Madrid, Spain
- Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, Universitat de Barcelona, Barcelona, Spain
| | - Peter Kolb
- Department of Pharmaceutical Chemistry, University of Marburg, Marbacher Weg 6, 35037, Marburg, Germany
| | - Paolo Annibale
- Max Delbrück Center for Molecular Medicine, Berlin, 13125, Germany
- School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Scotland
| | - Steffen Pockes
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053, Regensburg, Germany
- Department of Medicinal Chemistry, Institute for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, MN, 55414, USA
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5
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Rosier N, Mönnich D, Nagl M, Schihada H, Sirbu A, Konar N, Reyes-Resina I, Navarro G, Franco R, Kolb P, Annibale P, Pockes S. Shedding Light on the D 1 -Like Receptors: A Fluorescence-Based Toolbox for Visualization of the D 1 and D 5 Receptors. Chembiochem 2024; 25:e202300658. [PMID: 37983731 DOI: 10.1002/cbic.202300658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 11/08/2023] [Indexed: 11/22/2023]
Abstract
Dopamine D1 -like receptors are the most abundant type of dopamine receptors in the central nervous system and, even after decades of discovery, still highly interesting for the study of neurological diseases. We herein describe the synthesis of a new set of fluorescent ligands, structurally derived from D1 R antagonist SCH-23390 and labeled with two different fluorescent dyes, as tool compounds for the visualization of D1 -like receptors. Pharmacological characterization in radioligand binding studies identified UR-NR435 (25) as a high-affinity ligand for D1 -like receptors (pKi (D1 R)=8.34, pKi (D5 R)=7.62) with excellent selectivity towards D2 -like receptors. Compound 25 proved to be a neutral antagonist at the D1 R and D5 R in a Gs heterotrimer dissociation assay, an important feature to avoid receptor internalization and degradation when working with whole cells. The neutral antagonist 25 displayed rapid association and complete dissociation to the D1 R in kinetic binding studies using confocal microscopy verifying its applicability for fluorescence microscopy. Moreover, molecular brightness studies determined a single-digit nanomolar binding affinity of the ligand, which was in good agreement with radioligand binding data. For this reason, this fluorescent ligand is a useful tool for a sophisticated characterization of native D1 receptors in a variety of experimental setups.
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Affiliation(s)
- Niklas Rosier
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Denise Mönnich
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Martin Nagl
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Hannes Schihada
- Department of Pharmaceutical Chemistry, University of Marburg, Marbacher Weg 6, 35037, Marburg, Germany
| | - Alexei Sirbu
- Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany
| | - Nergis Konar
- Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany
| | - Irene Reyes-Resina
- CiberNed, Network Center for Neurodegenerative Diseases, National Spanish Health Institute Carlos III, Madrid, Spain
- Department Biochemistry and Physiology, School of Pharmacy and Food Sciences, Universitat de Barcelona, Barcelona, Spain
| | - Gemma Navarro
- CiberNed, Network Center for Neurodegenerative Diseases, National Spanish Health Institute Carlos III, Madrid, Spain
- Department Biochemistry and Physiology, School of Pharmacy and Food Sciences, Universitat de Barcelona, Barcelona, Spain
| | - Rafael Franco
- CiberNed, Network Center for Neurodegenerative Diseases, National Spanish Health Institute Carlos III, Madrid, Spain
- Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, Universitat de Barcelona, Barcelona, Spain
| | - Peter Kolb
- Department of Pharmaceutical Chemistry, University of Marburg, Marbacher Weg 6, 35037, Marburg, Germany
| | - Paolo Annibale
- Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany
- School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews, Scotland, UK
| | - Steffen Pockes
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
- Department of Medicinal Chemistry, Institute for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, MN 55414, USA
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6
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Ray M, Sayeed A, Ganshert M, Saha A. Direct Binding Methods to Measure Receptor-Ligand Interactions. J Phys Chem B 2024; 128:3-19. [PMID: 38134048 DOI: 10.1021/acs.jpcb.3c05041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2023]
Abstract
G-protein-coupled receptors (GPCRs) contribute to numerous physiological processes via complex network mechanisms. While indirect signaling assays (Ca2+ mobilization, cAMP production, and GTPγS binding) have been useful in identifying and characterizing downstream signaling mechanisms of GPCRs, these methods lack measurements of direct binding affinities, kinetics, binding specificity, and selectivity that are important parameters in GPCR drug discovery. In comparison to existing direct methods that use radio- or fluorescent labels, label-free techniques can closely emulate the native interactions around binding partners. Surface plasmon resonance (SPR) is a label-free technique that utilizes the refractive index (RI) property and is applied widely in quantitative GPCR-ligand binding kinetics measurement including small molecules screening. However, purified GPCRs are further embedded in a synthetic lipid environment which is immobilized through different tags to the SPR sensor surface, resulting in a non-native environment. Here, we introduced a methodology that also uses the RI property to measure binding interactions in a label-free, immobilization-free arrangement. The free-solution technique is successfully applied in quantifying the interaction of bioactive lipids to cognate lipid GPCRs, which is not purified but rather present in near-native conditions, i.e., in milieu of other cytoplasmic lipids and proteins. To further consider the wide applicability of these free-solution approaches in biomolecular interaction research, additional applications on a variety of receptor-ligand pairs are imperative.
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Affiliation(s)
- Manisha Ray
- Department of Chemistry and Biochemistry, Loyola University Chicago, 1068 W. Sheridan Road, Chicago, Illinois 60660, United States
| | - Aryana Sayeed
- Department of Chemistry and Biochemistry, Loyola University Chicago, 1068 W. Sheridan Road, Chicago, Illinois 60660, United States
| | - Madeline Ganshert
- Department of Chemistry and Biochemistry, Loyola University Chicago, 1068 W. Sheridan Road, Chicago, Illinois 60660, United States
| | - Arjun Saha
- Department of Chemistry and Biochemistry, University of Wisconsin, Milwaukee Chemistry Bldg, 144, 3210 N Cramer Street, Milwaukee, Wisconsin 53211, United States
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7
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Daubermann AG, Dressano K, de Oliveira Ceciliato PH, Moura DS. Acridinium-Based Chemiluminescent Receptor-Ligand Binding Assay for Protein/Peptide Hormones. Methods Mol Biol 2024; 2731:253-263. [PMID: 38019440 DOI: 10.1007/978-1-0716-3511-7_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2023]
Abstract
Chemiluminescent acridinium esters (AE) have been extensively used for oligonucleotide probing and peptide-binding assays in molecular research due to labeling efficiency, lack of radioactivity, and ease of application. In addition to being a powerful and reliable alternative to radiolabeling, AE can be directly bound to the target molecule, with high specificity. Here, we describe an AE-based protein/peptide labeling method and the use of the labeled protein/peptide in a ligand-binding assay.
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Affiliation(s)
- André Guilherme Daubermann
- Laboratório de Bioquímica de Proteínas, Departamento de Ciências Biológicas, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo (ESALQ/USP), Piracicaba, Brazil
| | - Keini Dressano
- Laboratório de Bioquímica de Proteínas, Departamento de Ciências Biológicas, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo (ESALQ/USP), Piracicaba, Brazil
- Centro de Tecnologia Canavieira - CTC, Piracicaba, Brazil
| | - Paulo Henrique de Oliveira Ceciliato
- Laboratório de Bioquímica de Proteínas, Departamento de Ciências Biológicas, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo (ESALQ/USP), Piracicaba, Brazil
- Centro de Tecnologia Canavieira - CTC, Piracicaba, Brazil
| | - Daniel S Moura
- Laboratório de Bioquímica de Proteínas, Departamento de Ciências Biológicas, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo (ESALQ/USP), Piracicaba, Brazil.
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8
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Bresinsky M, Shahraki A, Kolb P, Pockes S, Schihada H. Development of Fluorescent AF64394 Analogues Enables Real-Time Binding Studies for the Orphan Class A GPCR GPR3. J Med Chem 2023; 66:15025-15041. [PMID: 37907069 PMCID: PMC10641823 DOI: 10.1021/acs.jmedchem.3c01707] [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] [Received: 09/14/2023] [Revised: 10/16/2023] [Accepted: 10/18/2023] [Indexed: 11/02/2023]
Abstract
The orphan G protein-coupled receptor (oGPCR) GPR3 represents a potential drug target for the treatment of Alzheimer's disease and metabolic disorders. However, the limited toolbox of pharmacological assays hampers the development of advanced ligands. Here, we developed a signaling pathway-independent readout of compound-GPR3 interaction. Starting from computational binding pose predictions of the most potent GPR3 ligand, we designed a series of fluorescent AF64394 analogues and assessed their suitability for BRET-based binding studies. The most potent ligand, 45 (UR-MB-355), bound to GPR3 and closely related receptors, GPR6 and GPR12, with similar submicromolar affinities. Furthermore, we found that 45 engages GPR3 in a distinct mode compared to AF64394, and coincubation studies with the GPR3 agonist diphenyleneiodonium chloride revealed allosteric modulation of 45 binding. These insights provide new cues for the pharmacological manipulation of GPR3 activity. This novel binding assay will foster the development of future drugs acting through these pharmacologically attractive oGPCRs.
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Affiliation(s)
- Merlin Bresinsky
- Institute
of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Aida Shahraki
- Department
of Pharmaceutical Chemistry, University
of Marburg, Marbacher Weg 8, 35032 Marburg, Germany
| | - Peter Kolb
- Department
of Pharmaceutical Chemistry, University
of Marburg, Marbacher Weg 8, 35032 Marburg, Germany
| | - Steffen Pockes
- Institute
of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
- Department
of Medicinal Chemistry, Institute for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Hannes Schihada
- Department
of Pharmaceutical Chemistry, University
of Marburg, Marbacher Weg 8, 35032 Marburg, Germany
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9
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Archipowa N, Wittmann L, Köckenberger J, Ertl FJ, Gleixner J, Keller M, Heinrich MR, Kutta RJ. Characterization of Fluorescent Dyes Frequently Used for Bioimaging: Photophysics and Photocatalytical Reactions with Proteins. J Phys Chem B 2023; 127:9532-9542. [PMID: 37903729 DOI: 10.1021/acs.jpcb.3c04484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2023]
Abstract
Derivatives of the rhodamine-based dye 5-TAMRA (5-carboxy-tetramethylrhodamine) and the indocarbocyanine-type Cy3B (cyclized derivative of the cyanine dye Cy3), both representing important fluorophores frequently used for the labeling of biomolecules (proteins, nucleic acids) and bioactive compounds, such as receptor ligands, were photophysically investigated in aqueous solution, i.e., in neat phosphate-buffered saline (PBS) and in PBS supplemented with 1 wt % bovine serum albumin (BSA). The dyes exhibit comparable absorption (λabs,max: 550-569 nm) and emission wavelengths (λem,max: 580-582 nm), and similar S1 lifetimes (2.27-2.75 ns), and their excited state deactivation proceeds mainly via the lowest excited singlet state (triplet quantum yield ca. 1%). However, the probes show marked differences with respect to their fluorescence quantum yield and photostability. While 5-TAMRA shows a lower quantum yield (37-39%) than the Cy3B derivative (ca. 57%), its photostability is considerably higher compared to Cy3B. Generally, the impact of the protein on the photophysics is low. However, on prolonged illumination, both fluorescent dyes undergo a photocatalytic reaction with tryptophan residues of BSA mediated by sensitized singlet oxygen resulting in a tryptophan photoproduct with an absorption maximum around 330 nm. The overall results of this work will assist in choosing the right dye for the labeling of bioactive compounds, and the study demonstrates that experiments performed with 5-TAMRA or Cy3B-labeled compounds in a biological environment may be influenced by photochemical modification of experimentally relevant proteins at aromatic amino acid residues.
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Affiliation(s)
- Nataliya Archipowa
- Institute of Biophysics and Physical Biochemistry, Faculty of Biology and Preclinical Medicine, University of Regensburg, D-93053 Regensburg, Germany
| | - Lukas Wittmann
- Institute of Physical and Theoretical Chemistry, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Johannes Köckenberger
- Department of Chemistry and Pharmacy, Molecular and Clinical Pharmacy, Friedrich-Alexander-University Erlangen-Nürnberg, Nikolaus-Fiebiger-Straße 10, D-91058 Erlangen, Germany
| | - Fabian J Ertl
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Jakob Gleixner
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Max Keller
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Markus R Heinrich
- Department of Chemistry and Pharmacy, Molecular and Clinical Pharmacy, Friedrich-Alexander-University Erlangen-Nürnberg, Nikolaus-Fiebiger-Straße 10, D-91058 Erlangen, Germany
| | - Roger Jan Kutta
- Institute of Physical and Theoretical Chemistry, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
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10
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Ullrich M, Brandt F, Löser R, Pietzsch J, Wodtke R. Comparative Saturation Binding Analysis of 64Cu-Labeled Somatostatin Analogues Using Cell Homogenates and Intact Cells. ACS OMEGA 2023; 8:24003-24009. [PMID: 37426243 PMCID: PMC10324063 DOI: 10.1021/acsomega.3c02755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 06/09/2023] [Indexed: 07/11/2023]
Abstract
The development of novel ligands for G-protein-coupled receptors (GPCRs) typically entails the characterization of their binding affinity, which is often performed with radioligands in a competition or saturation binding assay format. Since GPCRs are transmembrane proteins, receptor samples for binding assays are prepared from tissue sections, cell membranes, cell homogenates, or intact cells. As part of our investigations on modulating the pharmacokinetics of radiolabeled peptides for improved theranostic targeting of neuroendocrine tumors with a high abundance of the somatostatin receptor sub-type 2 (SST2), we characterized a series of 64Cu-labeled [Tyr3]octreotate (TATE) derivatives in vitro in saturation binding assays. Herein, we report on the SST2 binding parameters measured toward intact mouse pheochromocytoma cells and corresponding cell homogenates and discuss the observed differences taking the physiology of SST2 and GPCRs in general into account. Furthermore, we point out method-specific advantages and limitations.
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Affiliation(s)
- Martin Ullrich
- Helmholtz-Zentrum
Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, Dresden 01328, Germany
| | - Florian Brandt
- Helmholtz-Zentrum
Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, Dresden 01328, Germany
- School
of Science, Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Mommsenstraße 4, Dresden 01069, Germany
| | - Reik Löser
- Helmholtz-Zentrum
Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, Dresden 01328, Germany
- School
of Science, Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Mommsenstraße 4, Dresden 01069, Germany
| | - Jens Pietzsch
- Helmholtz-Zentrum
Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, Dresden 01328, Germany
- School
of Science, Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Mommsenstraße 4, Dresden 01069, Germany
| | - Robert Wodtke
- Helmholtz-Zentrum
Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, Dresden 01328, Germany
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11
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Lay CS, Isidro-Llobet A, Kilpatrick LE, Craggs PD, Hill SJ. Characterisation of IL-23 receptor antagonists and disease relevant mutants using fluorescent probes. Nat Commun 2023; 14:2882. [PMID: 37208328 PMCID: PMC10199020 DOI: 10.1038/s41467-023-38541-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 05/08/2023] [Indexed: 05/21/2023] Open
Abstract
Association of single nucleotide polymorphisms in the IL-23 receptor with several auto-inflammatory diseases, led to the heterodimeric receptor and its cytokine-ligand IL-23, becoming important drug targets. Successful antibody-based therapies directed against the cytokine have been licenced and a class of small peptide antagonists of the receptor have entered clinical trials. These peptide antagonists may offer therapeutic advantages over existing anti-IL-23 therapies, but little is known about their molecular pharmacology. In this study, we use a fluorescent version of IL-23 to characterise antagonists of the full-length receptor expressed by living cells using a NanoBRET competition assay. We then develop a cyclic peptide fluorescent probe, specific to the IL23p19:IL23R interface and use this molecule to characterise further receptor antagonists. Finally, we use the assays to study the immunocompromising C115Y IL23R mutation, demonstrating that the mechanism of action is a disruption of the binding epitope for IL23p19.
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Affiliation(s)
- Charles S Lay
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, NG7 2UH, UK
- Centre of Membrane Proteins and Receptors, University of Birmingham and Nottingham, The Midlands, UK
- Chemical Biology, Medicine Design, GlaxoSmithKline, Stevenage, SG1 2NY, UK
| | | | - Laura E Kilpatrick
- Centre of Membrane Proteins and Receptors, University of Birmingham and Nottingham, The Midlands, UK
- Division of Bimolecular Science and Medicinal Chemistry, School of Pharmacy, Biodiscovery Institute, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Peter D Craggs
- Chemical Biology, Medicine Design, GlaxoSmithKline, Stevenage, SG1 2NY, UK.
- Crick-GSK Biomedical Linklabs, Medicine Design, GlaxoSmithKline, Stevenage, SG1 2NY, UK.
| | - Stephen J Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, NG7 2UH, UK.
- Centre of Membrane Proteins and Receptors, University of Birmingham and Nottingham, The Midlands, UK.
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12
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Williams TL, Macrae RGC, Kuc RE, Brown AJH, Maguire JJ, Davenport AP. Expanding the apelin receptor pharmacological toolbox using novel fluorescent ligands. Front Endocrinol (Lausanne) 2023; 14:1139121. [PMID: 36967803 PMCID: PMC10034064 DOI: 10.3389/fendo.2023.1139121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 02/24/2023] [Indexed: 03/11/2023] Open
Abstract
INTRODUCTION The apelin receptor binds two distinct endogenous peptides, apelin and ELA, which act in an autocrine/paracrine manner to regulate the human cardiovascular system. As a class A GPCR, targeting the apelin receptor is an attractive therapeutic strategy. With improvements in imaging techniques, and the stability and brightness of dyes, fluorescent ligands are becoming increasingly useful in studying protein targets. Here, we describe the design and validation of four novel fluorescent ligands; two based on [Pyr1]apelin-13 (apelin488 and apelin647), and two based on ELA-14 (ELA488 and ELA647). METHODS Fluorescent ligands were pharmacologically assessed using radioligand and functional in vitro assays. Apelin647 was validated in high content imaging and internalisation studies, and in a clinically relevant human embryonic stem cell-derived cardiomyocyte model. Apelin488 and ELA488 were used to visualise apelin receptor binding in human renal tissue. RESULTS All four fluorescent ligands retained the ability to bind and activate the apelin receptor and, crucially, triggered receptor internalisation. In high content imaging studies, apelin647 bound specifically to CHO-K1 cells stably expressing apelin receptor, providing proof-of-principle for a platform that could screen novel hits targeting this GPCR. The ligand also bound specifically to endogenous apelin receptor in stem cell-derived cardiomyocytes. Apelin488 and ELA488 bound specifically to apelin receptor, localising to blood vessels and tubules of the renal cortex. DISCUSSION Our data indicate that the described novel fluorescent ligands expand the pharmacological toolbox for studying the apelin receptor across multiple platforms to facilitate drug discovery.
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Affiliation(s)
- Thomas L. Williams
- Experimental Medicine & Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom
| | - Robyn G. C. Macrae
- Experimental Medicine & Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom
- Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, University of Cambridge, Cambridge, United Kingdom
| | - Rhoda E. Kuc
- Experimental Medicine & Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom
| | | | - Janet J. Maguire
- Experimental Medicine & Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom
| | - Anthony P. Davenport
- Experimental Medicine & Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom
- *Correspondence: Anthony P. Davenport,
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13
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Köckenberger J, Fischer O, Konopa A, Bergwinkl S, Mühlich S, Gmeiner P, Kutta RJ, Hübner H, Keller M, Heinrich MR. Synthesis, Characterization, and Application of Muscarinergic M 3 Receptor Ligands Linked to Fluorescent Dyes. J Med Chem 2022; 65:16494-16509. [PMID: 36484801 DOI: 10.1021/acs.jmedchem.2c01376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Through the linkage of two muscarinergic M3 receptor ligands to fluorescent tetramethylrhodamine- and cyanine-5-type dyes, two novel tool compounds, OFH5503 and OFH611, have been developed. Based on the suitable binding properties and kinetics related to the M3 subtype, both ligand-dye conjugates were found to be useful tools to determine binding affinities via flow cytometric measurements. In addition, confocal microscopy underlined the comparably low unspecific binding and the applicability for studying M3 receptor expression in cells. Along with the proven usefulness regarding studies on the M3 subtype, the conjugates OFH5503 and OFH611 could, due to their high affinity to the M1 receptor, evolve as even more versatile tools in the field of research on muscarinergic receptors.
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Affiliation(s)
- Johannes Köckenberger
- Department of Chemistry and Pharmacy, Pharmaceutical Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Nikolaus-Fiebiger-Str. 10, 91058 Erlangen, Germany
| | - Oliver Fischer
- Department of Chemistry and Pharmacy, Pharmaceutical Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Nikolaus-Fiebiger-Str. 10, 91058 Erlangen, Germany
| | - Andreas Konopa
- Department of Chemistry and Pharmacy, Molecular and Clinical Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg, Nikolaus-Fiebiger-Str. 10, 91058 Erlangen, Germany
| | - Sebastian Bergwinkl
- Institute of Physical and Theoretical Chemistry, University of Regensburg, D-93040 Regensburg, Germany
| | - Susanne Mühlich
- Department of Chemistry and Pharmacy, Molecular and Clinical Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg, Nikolaus-Fiebiger-Str. 10, 91058 Erlangen, Germany
| | - Peter Gmeiner
- Department of Chemistry and Pharmacy, Pharmaceutical Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Nikolaus-Fiebiger-Str. 10, 91058 Erlangen, Germany
| | - Roger Jan Kutta
- Institute of Physical and Theoretical Chemistry, University of Regensburg, D-93040 Regensburg, Germany
| | - Harald Hübner
- Department of Chemistry and Pharmacy, Pharmaceutical Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Nikolaus-Fiebiger-Str. 10, 91058 Erlangen, Germany
| | - Max Keller
- Institute of Pharmacy, University of Regensburg, D-93040 Regensburg, Germany
| | - Markus R Heinrich
- Department of Chemistry and Pharmacy, Pharmaceutical Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Nikolaus-Fiebiger-Str. 10, 91058 Erlangen, Germany
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14
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Grätz L, Müller C, Pegoli A, Schindler L, Bernhardt G, Littmann T. Insertion of Nanoluc into the Extracellular Loops as a Complementary Method To Establish BRET-Based Binding Assays for GPCRs. ACS Pharmacol Transl Sci 2022; 5:1142-1155. [PMID: 36407949 PMCID: PMC9667534 DOI: 10.1021/acsptsci.2c00162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Indexed: 11/13/2022]
Abstract
Luminescence-based techniques play an increasingly important role in all areas of biochemical research, including investigations on G protein-coupled receptors (GPCRs). One quite recent and popular addition has been made by introducing bioluminescence resonance energy transfer (BRET)-based binding assays for GPCRs, which are based on the fusion of nanoluciferase (Nluc) to the N-terminus of the receptor and the occurring energy transfer via BRET to a bound fluorescent ligand. However, being based on BRET, the technique is strongly dependent on the distance/orientation between the luciferase and the fluorescent ligand. Here we describe an alternative strategy to establish BRET-based binding assays for GPCRs, where the N-terminal fusion of Nluc did not result in functioning test systems with our fluorescent ligands (e.g., for the neuropeptide Y Y1 receptor (Y1R) and the neurotensin receptor type 1 (NTS1R)). Instead, we introduced Nluc into their second extracellular loop and we obtained binding data for the fluorescent ligands and reported standard ligands (in saturation and competition binding experiments, respectively) comparable to data from the literature. The strategy was transferred to the angiotensin II receptor type 1 (AT1R) and the M1 muscarinic acetylcholine receptor (M1R), which led to affinity estimates comparable to data from radioligand binding experiments. Additionally, an analysis of the binding kinetics of all fluorescent ligands at their respective target was performed using the newly described receptor/Nluc-constructs.
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Affiliation(s)
| | - Christoph Müller
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | | | - Lisa Schindler
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Günther Bernhardt
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
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15
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Farmer JP, Mistry SN, Laughton CA, Holliday ND. Development of fluorescent peptide G protein-coupled receptor activation biosensors for NanoBRET characterization of intracellular allosteric modulators. FASEB J 2022; 36:e22576. [PMID: 36183332 DOI: 10.1096/fj.202201024r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 09/02/2022] [Accepted: 09/19/2022] [Indexed: 11/11/2022]
Abstract
G protein-coupled receptors (GPCRs) are widely therapeutically targeted, and recent advances in allosteric modulator development at these receptors offer further potential for exploitation. Intracellular allosteric modulators (IAM) represent a class of ligands that bind to the receptor-effector interface (e.g., G protein) and inhibit agonist responses noncompetitively. This potentially offers greater selectivity between receptor subtypes compared to classical orthosteric ligands. However, while examples of IAM ligands are well described, a more general methodology for assessing compound interactions at the IAM site is lacking. Here, fluorescent labeled peptides based on the Gα peptide C terminus are developed as novel binding and activation biosensors for the GPCR-IAM site. In TR-FRET binding studies, unlabeled peptides derived from the Gαs subunit were first characterized for their ability to positively modulate agonist affinity at the β2 -adrenoceptor. On this basis, a tetramethylrhodamine (TMR) labeled tracer was synthesized based on the 19 amino acid Gαs peptide (TMR-Gαs19cha18, where cha = cyclohexylalanine). Using NanoBRET technology to detect binding, TMR-Gαs19cha18 was recruited to Gs coupled β2 -adrenoceptor and EP2 receptors in an agonist-dependent manner, but not the Gi-coupled CXCR2 receptor. Moreover, NanoBRET competition binding assays using TMR-Gαs19cha18 enabled direct assessment of the affinity of unlabeled ligands for β2 -adrenoceptor IAM site. Thus, the NanoBRET platform using fluorescent-labeled G protein peptide mimetics offers novel potential for medium-throughput screens to identify IAMs, applicable across GPCRs coupled to a G protein class. Using the same platform, Gs peptide biosensors also represent useful tools to probe orthosteric agonist efficacy and the dynamics of receptor activation.
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Affiliation(s)
- James P Farmer
- School of Life Sciences, The Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, Nottingham, UK
| | | | | | - Nicholas D Holliday
- School of Life Sciences, The Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, UK.,Excellerate Bioscience, Biocity, Nottingham, UK
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16
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Gbahou F, Levin S, Tikhonova IG, Somalo Barranco G, Izabelle C, Ohana RF, Jockers R. Luminogenic HiBiT Peptide-Based NanoBRET Ligand Binding Assays for Melatonin Receptors. ACS Pharmacol Transl Sci 2022; 5:668-678. [DOI: 10.1021/acsptsci.2c00096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Indexed: 11/28/2022]
Affiliation(s)
- Florence Gbahou
- Université Paris Cité, Institut Cochin, INSERM, CNRS, 75014 Paris, France
| | - Sergiy Levin
- Promega Corporation, Fitchburg, Wisconsin 53711, United States
| | - Irina G. Tikhonova
- School of Pharmacy, Medical Biology Centre, Queen’s University Belfast, Belfast BT9 7BL, United Kingdom
| | | | - Charlotte Izabelle
- Université Paris Cité, Institut Cochin, INSERM, CNRS, 75014 Paris, France
| | | | - Ralf Jockers
- Université Paris Cité, Institut Cochin, INSERM, CNRS, 75014 Paris, France
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17
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Tahk MJ, Torp J, Ali MAS, Fishman D, Parts L, Grätz L, Müller C, Keller M, Veiksina S, Laasfeld T, Rinken A. Live-cell microscopy or fluorescence anisotropy with budded baculoviruses-which way to go with measuring ligand binding to M 4 muscarinic receptors? Open Biol 2022; 12:220019. [PMID: 35674179 PMCID: PMC9175271 DOI: 10.1098/rsob.220019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 04/27/2022] [Indexed: 01/04/2023] Open
Abstract
M4 muscarinic acetylcholine receptor is a G protein-coupled receptor (GPCR) that has been associated with alcohol and cocaine abuse, Alzheimer's disease, and schizophrenia which makes it an interesting drug target. For many GPCRs, the high-affinity fluorescence ligands have expanded the options for high-throughput screening of drug candidates and serve as useful tools in fundamental receptor research. Here, we explored two TAMRA-labelled fluorescence ligands, UR-MK342 and UR-CG072, for development of assays for studying ligand-binding properties to M4 receptor. Using budded baculovirus particles as M4 receptor preparation and fluorescence anisotropy method, we measured the affinities and binding kinetics of both fluorescence ligands. Using the fluorescence ligands as reporter probes, the binding affinities of unlabelled ligands could be determined. Based on these results, we took a step towards a more natural system and developed a method using live CHO-K1-hM4R cells and automated fluorescence microscopy suitable for the routine determination of unlabelled ligand affinities. For quantitative image analysis, we developed random forest and deep learning-based pipelines for cell segmentation. The pipelines were integrated into the user-friendly open-source Aparecium software. Both image analysis methods were suitable for measuring fluorescence ligand saturation binding and kinetics as well as for screening binding affinities of unlabelled ligands.
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Affiliation(s)
- Maris-Johanna Tahk
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Jane Torp
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Mohammed A. S. Ali
- Department of Computer Science, University of Tartu, Narva Street 20, 51009 Tartu, Estonia
| | - Dmytro Fishman
- Department of Computer Science, University of Tartu, Narva Street 20, 51009 Tartu, Estonia
| | - Leopold Parts
- Department of Computer Science, University of Tartu, Narva Street 20, 51009 Tartu, Estonia
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK
| | - Lukas Grätz
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Christoph Müller
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Max Keller
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Santa Veiksina
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Tõnis Laasfeld
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
- Department of Computer Science, University of Tartu, Narva Street 20, 51009 Tartu, Estonia
| | - Ago Rinken
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
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18
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Yeast-based directed-evolution for high-throughput structural stabilization of G protein-coupled receptors (GPCRs). Sci Rep 2022; 12:8657. [PMID: 35606532 PMCID: PMC9126886 DOI: 10.1038/s41598-022-12731-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 05/10/2022] [Indexed: 11/08/2022] Open
Abstract
The immense potential of G protein-coupled receptors (GPCRs) as targets for drug discovery is not fully realized due to the enormous difficulties associated with structure elucidation of these profoundly unstable membrane proteins. The existing methods of GPCR stability-engineering are cumbersome and low-throughput; in addition, the scope of GPCRs that could benefit from these techniques is limited. Here, we present a yeast-based screening platform for a single-step isolation of GRCR variants stable in the presence of short-chain detergents, a feature essential for their successful crystallization using vapor diffusion method. The yeast detergent-resistant cell wall presents a unique opportunity for compartmentalization, to physically link the receptor's phenotype to its encoding DNA, and thus enable discovery of stable GPCR variants with unprecedent efficiency. The scope of mutations identified by the method reveals a surprising amenability of the GPCR scaffold to stabilization, and suggests an intriguing possibility of amending the stability properties of GPCR by varying the structural status of the C-terminus.
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19
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Intercellular Communication in the Central Nervous System as Deduced by Chemical Neuroanatomy and Quantitative Analysis of Images: Impact on Neuropharmacology. Int J Mol Sci 2022; 23:ijms23105805. [PMID: 35628615 PMCID: PMC9145073 DOI: 10.3390/ijms23105805] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/19/2022] [Accepted: 05/20/2022] [Indexed: 01/25/2023] Open
Abstract
In the last decades, new evidence on brain structure and function has been acquired by morphological investigations based on synergic interactions between biochemical anatomy approaches, new techniques in microscopy and brain imaging, and quantitative analysis of the obtained images. This effort produced an expanded view on brain architecture, illustrating the central nervous system as a huge network of cells and regions in which intercellular communication processes, involving not only neurons but also other cell populations, virtually determine all aspects of the integrative function performed by the system. The main features of these processes are described. They include the two basic modes of intercellular communication identified (i.e., wiring and volume transmission) and mechanisms modulating the intercellular signaling, such as cotransmission and allosteric receptor–receptor interactions. These features may also open new possibilities for the development of novel pharmacological approaches to address central nervous system diseases. This aspect, with a potential major impact on molecular medicine, will be also briefly discussed.
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20
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An original approach to measure ligand/receptor binding affinity in non-purified samples. Sci Rep 2022; 12:5400. [PMID: 35354858 PMCID: PMC8967833 DOI: 10.1038/s41598-022-09217-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 03/10/2022] [Indexed: 11/30/2022] Open
Abstract
Several biochemical and biophysical methods are available to determine ligand binding affinities between a biological target and its ligands, most of which require purification, labelling or surface immobilisation. These measurements, however, remain challenging in regards to membrane proteins, as purification processes require their extraction from their native lipid environment, which may in turn impact receptor conformation and functionality. In this study, we have developed a novel experimental procedure using microscale thermophoresis (MST) directly from cell membrane fragments, to determine different ligand binding affinities to a membrane protein, the dopamine D2 receptor (D2R). In order to achieve this, two main challenges had to be overcome: determining the concentration of dopamine D2R in the crude sample; finding ways to minimize or account for non-specific binding of the ligand to cell fragments. Using MST, we were able to determine the D2R concentration in cell membrane fragments to approximately 36.8 ± 2.6 pmol/mg. Next, the doses-responses curves allowed for the determination of KD, to approximately 5.3 ± 1.7 nM, which is very close to the reported value. Important details of the experimental procedure have been detailed in this paper to allow the application of this novel method to various membrane proteins.
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21
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Lay CS, Thomas DA, Evans JP, Campbell M, McCombe K, Phillipou AN, Gordon LJ, Jones EJ, Riching K, Mahmood M, Messenger C, Carver CE, Gatfield KM, Craggs PD. Development of an intracellular quantitative assay to measure compound binding kinetics. Cell Chem Biol 2022; 29:287-299.e8. [PMID: 34520747 DOI: 10.1016/j.chembiol.2021.07.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 06/09/2021] [Accepted: 07/23/2021] [Indexed: 02/08/2023]
Abstract
Contemporary drug discovery typically quantifies the effect of a molecule on a biological target using the equilibrium-derived measurements of IC50, EC50, or KD. Kinetic descriptors of drug binding are frequently linked with the effectiveness of a molecule in modulating a disease phenotype; however, these parameters are yet to be fully adopted in early drug discovery. Nanoluciferase bioluminescence resonance energy transfer (NanoBRET) can be used to measure interactions between fluorophore-conjugated probes and luciferase fused target proteins. Here, we describe an intracellular NanoBRET competition assay that can be used to quantify cellular kinetic rates of compound binding to nanoluciferase-fused bromodomain and extra-terminal (BET) proteins. Comparative rates are generated using a cell-free NanoBRET assay and by utilizing orthogonal recombinant protein-based methodologies. A screen of known pan-BET inhibitors is used to demonstrate the value of this approach in the investigation of kinetic selectivity between closely related proteins.
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Affiliation(s)
- Charles S Lay
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Medicine Design, Medicinal Science and Technology, GlaxoSmithKline, Stevenage SG1 2NY, UK
| | - Daniel A Thomas
- Medicine Design, Medicinal Science and Technology, GlaxoSmithKline, Stevenage SG1 2NY, UK; Arctoris, Oxford OX14 4SA, UK
| | - John P Evans
- Medicine Design, Medicinal Science and Technology, GlaxoSmithKline, Stevenage SG1 2NY, UK
| | - Matthew Campbell
- Medicine Design, Medicinal Science and Technology, GlaxoSmithKline, Stevenage SG1 2NY, UK
| | - Kristopher McCombe
- Medicine Design, Medicinal Science and Technology, GlaxoSmithKline, Stevenage SG1 2NY, UK; Patrick G. Johnston Centre for Cancer Research, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast BT9 7AE, UK
| | - Alexander N Phillipou
- Medicine Design, Medicinal Science and Technology, GlaxoSmithKline, Stevenage SG1 2NY, UK
| | - Laurie J Gordon
- Medicine Design, Medicinal Science and Technology, GlaxoSmithKline, Stevenage SG1 2NY, UK
| | - Emma J Jones
- Protein and Cellular Sciences, Medicinal Science and Technology, GlaxoSmithKline, Stevenage SG1 2NY, UK
| | | | - Mahnoor Mahmood
- Medicine Design, Medicinal Science and Technology, GlaxoSmithKline, Stevenage SG1 2NY, UK
| | - Cassie Messenger
- Medicine Design, Medicinal Science and Technology, GlaxoSmithKline, Stevenage SG1 2NY, UK
| | - Charlotte E Carver
- Medicine Design, Medicinal Science and Technology, GlaxoSmithKline, Stevenage SG1 2NY, UK
| | - Kelly M Gatfield
- Medicine Design, Medicinal Science and Technology, GlaxoSmithKline, Stevenage SG1 2NY, UK
| | - Peter D Craggs
- Medicine Design, Medicinal Science and Technology, GlaxoSmithKline, Stevenage SG1 2NY, UK; GSK-Francis Crick Institute Linklabs, Medicinal Science and Technology, GlaxoSmithKline, Stevenage SG1 2NY, UK.
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22
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Green CM, Mathur D, Susumu K, Oh E, Medintz IL, Díaz SA. Polyhistidine-Tag-Enabled Conjugation of Quantum Dots and Enzymes to DNA Nanostructures. Methods Mol Biol 2022; 2525:61-91. [PMID: 35836061 DOI: 10.1007/978-1-0716-2473-9_6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
DNA nanostructures self-assemble into almost any arbitrary architecture, and when combined with their capability to precisely position and orient dyes, nanoparticles, and biological moieties, the technology reaches its potential. We present a simple yet multifaceted conjugation strategy based on metal coordination by a multi-histidine peptide tag (Histag). The versatility of the Histag as a means to conjugate to DNA nanostructures is shown by using Histags to capture semiconductor quantum dots (QDs) with numerical and positional precision onto a DNA origami breadboard. Additionally, Histag-expressing enzymes, such as the bioluminescent luciferase, can also be captured to the DNA origami breadboard with similar precision. DNA nanostructure conjugation of the QDs or luciferase is confirmed through imaging and/or energy transfer to organic dyes integrated into the DNA nanostructure.
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Affiliation(s)
- Christopher M Green
- Center for Bio/Molecular Science and Engineering, U.S. Naval Research Laboratory Code 6900, Washington, DC, USA
- National Research Council, Washington, DC, USA
| | - Divita Mathur
- Center for Bio/Molecular Science and Engineering, U.S. Naval Research Laboratory Code 6900, Washington, DC, USA
- College of Science, George Mason University, Fairfax, VA, USA
| | - Kimihiro Susumu
- Optical Sciences Division, Code 5600, U.S. Naval Research Laboratory, Washington, DC, USA
- Jacobs Corporation, Hanover, MD, USA
| | - Eunkeu Oh
- Optical Sciences Division, Code 5600, U.S. Naval Research Laboratory, Washington, DC, USA
| | - Igor L Medintz
- Center for Bio/Molecular Science and Engineering, U.S. Naval Research Laboratory Code 6900, Washington, DC, USA
| | - Sebastián A Díaz
- Center for Bio/Molecular Science and Engineering, U.S. Naval Research Laboratory Code 6900, Washington, DC, USA.
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23
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Organoids in image-based phenotypic chemical screens. Exp Mol Med 2021; 53:1495-1502. [PMID: 34663938 PMCID: PMC8569209 DOI: 10.1038/s12276-021-00641-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 04/08/2021] [Accepted: 05/04/2021] [Indexed: 12/18/2022] Open
Abstract
Image-based phenotypic screening relies on the extraction of multivariate information from cells cultured under a large variety of conditions. Technical advances in high-throughput microscopy enable screening in increasingly complex and biologically relevant model systems. To this end, organoids hold great potential for high-content screening because they recapitulate many aspects of parent tissues and can be derived from patient material. However, screening is substantially more difficult in organoids than in classical cell lines from both technical and analytical standpoints. In this review, we present an overview of studies employing organoids for screening applications. We discuss the promises and challenges of small-molecule treatments in organoids and give practical advice on designing, running, and analyzing high-content organoid-based phenotypic screens.
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24
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Borgarelli C, Klingl YE, Escamilla-Ayala A, Munck S, Van Den Bosch L, De Borggraeve WM, Ismalaj E. Lighting Up the Plasma Membrane: Development and Applications of Fluorescent Ligands for Transmembrane Proteins. Chemistry 2021; 27:8605-8641. [PMID: 33733502 DOI: 10.1002/chem.202100296] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Indexed: 12/16/2022]
Abstract
Despite the fact that transmembrane proteins represent the main therapeutic targets for decades, complete and in-depth knowledge about their biochemical and pharmacological profiling is not fully available. In this regard, target-tailored small-molecule fluorescent ligands are a viable approach to fill in the missing pieces of the puzzle. Such tools, coupled with the ability of high-precision optical techniques to image with an unprecedented resolution at a single-molecule level, helped unraveling many of the conundrums related to plasma proteins' life-cycle and druggability. Herein, we review the recent progress made during the last two decades in fluorescent ligand design and potential applications in fluorescence microscopy of voltage-gated ion channels, ligand-gated ion channels and G-coupled protein receptors.
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Affiliation(s)
- Carlotta Borgarelli
- Department of Chemistry, Molecular Design and Synthesis, KU Leuven Campus Arenberg Celestijnenlaan 200F -, box 2404, 3001, Leuven, Belgium
| | - Yvonne E Klingl
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven Campus Gasthuisberg O&N5 -, box 602 Herestraat 49, 3000, Leuven, Belgium.,Laboratory of Neurobiology, VIB, Center for Brain &, Disease Research, VIB-KU Leuven Campus Gasthuisberg O&N5 -, box 602 Herestraat 49, 3000, Leuven, Belgium
| | - Abril Escamilla-Ayala
- Center for Brain & Disease Research, & VIB BioImaging Core, VIB-KU Leuven Campus Gasthuisberg O&N5 -, box 602 Herestraat 49, 3000, Leuven, Belgium.,Department of Neurosciences, Leuven Brain Institute, KU Leuven, Campus Gasthuisberg O&N5 - box 602 Herestraat 49, 3000, Leuven, Belgium
| | - Sebastian Munck
- Center for Brain & Disease Research, & VIB BioImaging Core, VIB-KU Leuven Campus Gasthuisberg O&N5 -, box 602 Herestraat 49, 3000, Leuven, Belgium.,Department of Neurosciences, Leuven Brain Institute, KU Leuven, Campus Gasthuisberg O&N5 - box 602 Herestraat 49, 3000, Leuven, Belgium
| | - Ludo Van Den Bosch
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven Campus Gasthuisberg O&N5 -, box 602 Herestraat 49, 3000, Leuven, Belgium.,Laboratory of Neurobiology, VIB, Center for Brain &, Disease Research, VIB-KU Leuven Campus Gasthuisberg O&N5 -, box 602 Herestraat 49, 3000, Leuven, Belgium
| | - Wim M De Borggraeve
- Department of Chemistry, Molecular Design and Synthesis, KU Leuven Campus Arenberg Celestijnenlaan 200F -, box 2404, 3001, Leuven, Belgium
| | - Ermal Ismalaj
- Department of Chemistry, Molecular Design and Synthesis, KU Leuven Campus Arenberg Celestijnenlaan 200F -, box 2404, 3001, Leuven, Belgium
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25
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Goulding J, Mistry SJ, Soave M, Woolard J, Briddon SJ, White CW, Kellam B, Hill SJ. Subtype selective fluorescent ligands based on ICI 118,551 to study the human β2-adrenoceptor in CRISPR/Cas9 genome-edited HEK293T cells at low expression levels. Pharmacol Res Perspect 2021; 9:e00779. [PMID: 34003582 PMCID: PMC8130569 DOI: 10.1002/prp2.779] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 03/30/2021] [Accepted: 03/31/2021] [Indexed: 12/18/2022] Open
Abstract
Fluorescent ligand technologies have proved to be powerful tools to improve our understanding of ligand‐receptor interactions. Here we have characterized a small focused library of nine fluorescent ligands based on the highly selective β2‐adrenoceptor (β2AR) antagonist ICI 118,551. The majority of fluorescent ICI 118,551 analogs had good affinity for the β2AR (pKD >7.0) with good selectivity over the β1AR (pKD <6.0). The most potent and selective ligands being 8c (ICI 118,551‐Gly‐Ala‐BODIPY‐FL‐X; β2AR pKD 7.48), 9c (ICI 118,551‐βAla‐βAla‐BODIPY‐FL‐X; β2AR pKD 7.48), 12a (ICI 118,551‐PEG‐BODIPY‐X‐630/650; β2AR pKD 7.56), and 12b (ICI 118,551‐PEG‐BODIPY‐FL; β2AR pKD 7.42). 9a (ICI 118,551‐βAla‐βAla‐BODIPY‐X‐630/650) had the highest affinity at recombinant β2ARs (pKD 7.57), but also exhibited significant binding affinity to the β1AR (pKD 6.69). Nevertheless, among the red fluorescent ligands, 9a had the best imaging characteristics in recombinant HEK293 T cells and labeling was mostly confined to the cell surface. In contrast, 12a showed the highest propensity to label intracellular β2ARs in HEK293 T cell expressing exogenous β2ARs. This suggests that a combination of the polyethylene glycol (PEG) linker and the BODIPY‐X‐630/650 makes this ICI 118,551 derivative particularly susceptible to crossing the cell membrane to access the intracellular β2ARs. We have also used these ligands in combination with CRISPR/Cas9 genome‐edited HEK293 T cells to undertake for the first time real‐time ligand binding to native HEK293 T β2ARs at low native receptor expression levels. These studies provided quantitative data on ligand‐binding characteristics but also allowed real‐time visualization of the ligand‐binding interactions in genome‐edited cells using NanoBRET luminescence imaging.
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Affiliation(s)
- Joëlle Goulding
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Sarah J Mistry
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK.,School of Pharmacy, University of Nottingham, Nottingham, UK
| | - Mark Soave
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Jeanette Woolard
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Stephen J Briddon
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Carl W White
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK.,Harry Perkins Institute of Medical Research and Centre for Medical Research, University of Western Australia, QEII Medical Centre, Nedlands, Western Australia, Australia.,Australian Research Council Centre for Personalised Therapeutics Technologies, Australia
| | - Barrie Kellam
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK.,School of Pharmacy, University of Nottingham, Nottingham, UK
| | - Stephen J Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
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26
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Killoran MP, Levin S, Boursier ME, Zimmerman K, Hurst R, Hall MP, Machleidt T, Kirkland TA, Friedman Ohana R. An Integrated Approach toward NanoBRET Tracers for Analysis of GPCR Ligand Engagement. Molecules 2021; 26:molecules26102857. [PMID: 34065854 PMCID: PMC8151276 DOI: 10.3390/molecules26102857] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/06/2021] [Accepted: 05/07/2021] [Indexed: 01/22/2023] Open
Abstract
Gaining insight into the pharmacology of ligand engagement with G-protein coupled receptors (GPCRs) under biologically relevant conditions is vital to both drug discovery and basic research. NanoLuc-based bioluminescence resonance energy transfer (NanoBRET) monitoring competitive binding between fluorescent tracers and unmodified test compounds has emerged as a robust and sensitive method to quantify ligand engagement with specific GPCRs genetically fused to NanoLuc luciferase or the luminogenic HiBiT peptide. However, development of fluorescent tracers is often challenging and remains the principal bottleneck for this approach. One way to alleviate the burden of developing a specific tracer for each receptor is using promiscuous tracers, which is made possible by the intrinsic specificity of BRET. Here, we devised an integrated tracer discovery workflow that couples machine learning-guided in silico screening for scaffolds displaying promiscuous binding to GPCRs with a blend of synthetic strategies to rapidly generate multiple tracer candidates. Subsequently, these candidates were evaluated for binding in a NanoBRET ligand-engagement screen across a library of HiBiT-tagged GPCRs. Employing this workflow, we generated several promiscuous fluorescent tracers that can effectively engage multiple GPCRs, demonstrating the efficiency of this approach. We believe that this workflow has the potential to accelerate discovery of NanoBRET fluorescent tracers for GPCRs and other target classes.
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Affiliation(s)
- Michael P. Killoran
- Promega Corporation, 2800 Woods Hollow, Fitchburg, WI 53711, USA; (M.P.K.); (M.E.B.); (K.Z.); (R.H.); (M.P.H.); (T.M.)
| | - Sergiy Levin
- Promega Biosciences LLC, 277 Granada Drive, San Luis Obispo, CA 93401, USA; (S.L.); (T.A.K.)
| | - Michelle E. Boursier
- Promega Corporation, 2800 Woods Hollow, Fitchburg, WI 53711, USA; (M.P.K.); (M.E.B.); (K.Z.); (R.H.); (M.P.H.); (T.M.)
| | - Kristopher Zimmerman
- Promega Corporation, 2800 Woods Hollow, Fitchburg, WI 53711, USA; (M.P.K.); (M.E.B.); (K.Z.); (R.H.); (M.P.H.); (T.M.)
| | - Robin Hurst
- Promega Corporation, 2800 Woods Hollow, Fitchburg, WI 53711, USA; (M.P.K.); (M.E.B.); (K.Z.); (R.H.); (M.P.H.); (T.M.)
| | - Mary P. Hall
- Promega Corporation, 2800 Woods Hollow, Fitchburg, WI 53711, USA; (M.P.K.); (M.E.B.); (K.Z.); (R.H.); (M.P.H.); (T.M.)
| | - Thomas Machleidt
- Promega Corporation, 2800 Woods Hollow, Fitchburg, WI 53711, USA; (M.P.K.); (M.E.B.); (K.Z.); (R.H.); (M.P.H.); (T.M.)
| | - Thomas A. Kirkland
- Promega Biosciences LLC, 277 Granada Drive, San Luis Obispo, CA 93401, USA; (S.L.); (T.A.K.)
| | - Rachel Friedman Ohana
- Promega Corporation, 2800 Woods Hollow, Fitchburg, WI 53711, USA; (M.P.K.); (M.E.B.); (K.Z.); (R.H.); (M.P.H.); (T.M.)
- Correspondence: ; Tel.: +1-608-274-1181
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27
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Dielectric Spectroscopy Based Detection of Specific and Nonspecific Cellular Mechanisms. SENSORS 2021; 21:s21093177. [PMID: 34063599 PMCID: PMC8124793 DOI: 10.3390/s21093177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 04/29/2021] [Accepted: 04/30/2021] [Indexed: 12/14/2022]
Abstract
Using radiofrequency dielectric spectroscopy, we have investigated the impact of the interaction between a G protein-coupled receptor (GPCR), the sterile2 α-factor receptor protein (Ste2), and its cognate agonist ligand, the α-factor pheromone, on the dielectric properties of the plasma membrane in living yeast cells (Saccharomyces cerevisiae). The dielectric properties of a cell suspension containing a saturating concentration of α-factor were measured over the frequency range 40Hz–110 MHz and compared to the behavior of a similarly prepared suspension of cells in the absence of α-factor. A spherical three-shell model was used to determine the electrical phase parameters for the yeast cells in both types of suspensions. The relative permittivity of the plasma membrane showed a significant increase after exposure to α-factor (by 0.06 ± 0.05). The equivalent experiment performed on yeast cells lacking the ability to express Ste2 showed no change in plasma membrane permittivity. Interestingly, a large change also occurred to the electrical properties of the cellular interior after the addition of α-factor to the cell suspending medium, whether or not the cells were expressing Ste2. We present a number of different complementary experiments performed on the yeast to support these dielectric data and interpret the results in terms of specific cellular reactions to the presence of α-factor.
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28
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Koretz KS, McGraw CE, Stradley S, Elbaradei A, Malmstadt N, Robinson AS. Characterization of binding kinetics of A 2AR to Gα s protein by surface plasmon resonance. Biophys J 2021; 120:1641-1649. [PMID: 33675761 DOI: 10.1016/j.bpj.2021.02.032] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 02/11/2021] [Accepted: 02/17/2021] [Indexed: 01/09/2023] Open
Abstract
Because of their surface localization, G protein-coupled receptors (GPCRs) are often pharmaceutical targets as they respond to a variety of extracellular stimuli (e.g., light, hormones, small molecules) that may activate or inhibit a downstream signaling response. The adenosine A2A receptor (A2AR) is a well-characterized GPCR that is expressed widely throughout the human body, with over 10 crystal structures determined. Truncation of the A2AR C-terminus is necessary for crystallization as this portion of the receptor is long and unstructured; however, previous work suggests shortening of the A2AR C-terminus from 412 to 316 amino acids (A2AΔ316R) ablates downstream signaling, as measured by cAMP production, to below that of constitutive full-length A2AR levels. As cAMP production is downstream of the first activation event-coupling of G protein to its receptor-investigating that first step in activation is important in understanding how the truncation effects native GPCR function. Here, using purified receptor and Gαs proteins, we characterize the association of A2AR and A2AΔ316R to Gαs with and without GDP or GTPγs using surface plasmon resonance (SPR). Gαs affinity for A2AR was greatest for apo-Gαs, moderately affected in the presence of GDP and nearly completely ablated by the addition of GTPγs. Truncation of the A2AR C-terminus (A2AΔ316R) decreased the affinity of the unliganded receptor for Gαs by ∼20%, suggesting small changes to binding can greatly impact downstream signaling.
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Affiliation(s)
- Kirsten S Koretz
- Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, Louisiana; Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania
| | - Claire E McGraw
- Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, Louisiana
| | - Steven Stradley
- Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, Louisiana
| | - Ahmed Elbaradei
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California
| | - Noah Malmstadt
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California
| | - Anne S Robinson
- Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, Louisiana; Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania.
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29
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Hamilton LJ, Walker M, Pattabiraman M, Zhong HA, Luedtke B, Chandra S. Novel curcumin analog (cis-trans curcumin) as ligand to adenosine receptors A 2A and A 2B: potential for therapeutics. Pharmacol Res 2021; 165:105410. [PMID: 33401004 PMCID: PMC7979524 DOI: 10.1016/j.phrs.2020.105410] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 12/22/2020] [Accepted: 12/23/2020] [Indexed: 02/06/2023]
Abstract
All four of the adenosine receptor (AR) subtypes mediate pain and have been targeted by pharmacologists to generate new therapeutics for chronic pain. The vanilloid phytochemicals, which include curcumin, capsaicin, and gingerol, have been shown to alleviate pain. However, there is little to no literature on the interaction of vanilloid phytochemicals with ARs. In this study, photochemical methods were used to generate a novel isomer of curcumin (cis-trans curcumin or CTCUR), and the interactions of both curcumin and CTCUR with the two Gs-linked AR subtypes were studied. Competitive binding assays, docking analysis, and confocal fluorescence microscopy were performed to measure binding affinity; cell survival assays were used to measure toxicity; and cAMP assays were performed to measure receptor activation. Competitive binding results indicated that CTCUR binds to both AR A2A and AR A2B with Ki values of 5 μM and 7 μM, respectively, which is consistent with our docking results. Fluorescence microscopy data also shows binding for A2B and A2A. Cell survival results show that CTCUR and CUR are nontoxic at the tested concentrations in these cell lines. Overall, our results suggest that vanilloid phytochemicals may be slightly modified to increase interaction with Gs-ARs, and thereby can be further explored to provide a novel class of non-opioid antinociceptives.
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Affiliation(s)
- Luke J Hamilton
- Department of Biology, University of Nebraska-Kearney, United States
| | - Michaela Walker
- Department of Biology, University of Nebraska-Kearney, United States
| | | | - Haizhen A Zhong
- Department of Chemistry, University of Nebraska-Omaha, United States
| | - Brandon Luedtke
- Department of Biology, University of Nebraska-Kearney, United States
| | - Surabhi Chandra
- Department of Biology, University of Nebraska-Kearney, United States.
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30
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Aldewachi H, Al-Zidan RN, Conner MT, Salman MM. High-Throughput Screening Platforms in the Discovery of Novel Drugs for Neurodegenerative Diseases. Bioengineering (Basel) 2021; 8:30. [PMID: 33672148 PMCID: PMC7926814 DOI: 10.3390/bioengineering8020030] [Citation(s) in RCA: 80] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/05/2021] [Accepted: 02/18/2021] [Indexed: 02/06/2023] Open
Abstract
Neurodegenerative diseases (NDDs) are incurable and debilitating conditions that result in progressive degeneration and/or death of nerve cells in the central nervous system (CNS). Identification of viable therapeutic targets and new treatments for CNS disorders and in particular, for NDDs is a major challenge in the field of drug discovery. These difficulties can be attributed to the diversity of cells involved, extreme complexity of the neural circuits, the limited capacity for tissue regeneration, and our incomplete understanding of the underlying pathological processes. Drug discovery is a complex and multidisciplinary process. The screening attrition rate in current drug discovery protocols mean that only one viable drug may arise from millions of screened compounds resulting in the need to improve discovery technologies and protocols to address the multiple causes of attrition. This has identified the need to screen larger libraries where the use of efficient high-throughput screening (HTS) becomes key in the discovery process. HTS can investigate hundreds of thousands of compounds per day. However, if fewer compounds could be screened without compromising the probability of success, the cost and time would be largely reduced. To that end, recent advances in computer-aided design, in silico libraries, and molecular docking software combined with the upscaling of cell-based platforms have evolved to improve screening efficiency with higher predictability and clinical applicability. We review, here, the increasing role of HTS in contemporary drug discovery processes, in particular for NDDs, and evaluate the criteria underlying its successful application. We also discuss the requirement of HTS for novel NDD therapies and examine the major current challenges in validating new drug targets and developing new treatments for NDDs.
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Affiliation(s)
- Hasan Aldewachi
- Biomolecular Sciences Research Centre, Sheffield Hallam University, Sheffield S1 1WB, UK;
- College of Pharmacy, Nineveh University, Mosul 41002, Iraq
| | - Radhwan N. Al-Zidan
- College of Pharmacy, University of Mosul, Mosul 41002, Iraq;
- School of Applied Sciences, Edinburgh Napier University, Edinburgh EH11 4BN, UK
| | - Matthew T. Conner
- School of Sciences, Research Institute in Healthcare Science, University of Wolverhampton, Wolverhampton WV1 1LY, UK;
| | - Mootaz M. Salman
- College of Pharmacy, University of Mosul, Mosul 41002, Iraq;
- Oxford Parkinson’s Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX1 3QX, UK
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31
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White CW, Kilpatrick LE, Pfleger KDG, Hill SJ. A nanoluciferase biosensor to investigate endogenous chemokine secretion and receptor binding. iScience 2021; 24:102011. [PMID: 33490919 PMCID: PMC7809502 DOI: 10.1016/j.isci.2020.102011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 12/10/2020] [Accepted: 12/28/2020] [Indexed: 11/30/2022] Open
Abstract
Secreted chemokines are critical mediators of cellular communication that elicit intracellular signaling by binding membrane-bound receptors. Here we demonstrate the development and use of a sensitive real-time approach to quantify secretion and receptor binding of native chemokines in live cells to better understand their molecular interactions and function. CRISPR/Cas9 genome editing was used to tag the chemokine CXCL12 with the nanoluciferase fragment HiBiT. CXCL12 secretion was subsequently monitored and quantified by luminescence output. Binding of tagged CXCL12 to either chemokine receptors or membrane glycosaminoglycans could be monitored due to the steric constraints of nanoluciferase complementation. Furthermore, binding of native CXCL12-HiBiT to AlexaFluor488-tagged CXCR4 chemokine receptors could also be distinguished from glycosaminoglycan binding and pharmacologically analyzed using BRET. These live cell approaches combine the sensitivity of nanoluciferase with CRISPR/Cas9 genome editing to detect, quantify, and monitor binding of low levels of native secreted proteins in real time.
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Affiliation(s)
- Carl W White
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology & Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK.,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK.,Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, QEII Medical Centre, Nedlands, WA 6009, Australia.,Australian Research Council Centre for Personalised Therapeutics Technologies, Australia
| | - Laura E Kilpatrick
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK.,School of Pharmacy, Biodiscovery Institute, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Kevin D G Pfleger
- Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, QEII Medical Centre, Nedlands, WA 6009, Australia.,Australian Research Council Centre for Personalised Therapeutics Technologies, Australia.,Dimerix Limited, Nedlands, WA 6009, Australia
| | - Stephen J Hill
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology & Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK.,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
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32
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Johnstone EKM, See HB, Abhayawardana RS, Song A, Rosengren KJ, Hill SJ, Pfleger KDG. Investigation of Receptor Heteromers Using NanoBRET Ligand Binding. Int J Mol Sci 2021; 22:1082. [PMID: 33499147 PMCID: PMC7866079 DOI: 10.3390/ijms22031082] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 01/19/2021] [Accepted: 01/19/2021] [Indexed: 12/20/2022] Open
Abstract
Receptor heteromerization is the formation of a complex involving at least two different receptors with pharmacology that is distinct from that exhibited by its constituent receptor units. Detection of these complexes and monitoring their pharmacology is crucial for understanding how receptors function. The Receptor-Heteromer Investigation Technology (Receptor-HIT) utilizes ligand-dependent modulation of interactions between receptors and specific biomolecules for the detection and profiling of heteromer complexes. Previously, the interacting biomolecules used in Receptor-HIT assays have been intracellular proteins, however in this study we have for the first time used bioluminescence resonance energy transfer (BRET) with fluorescently-labeled ligands to investigate heteromerization of receptors on the cell surface. Using the Receptor-HIT ligand binding assay with NanoBRET, we have successfully investigated heteromers between the angiotensin II type 1 (AT1) receptor and the β2 adrenergic receptor (AT1-β2AR heteromer), as well as between the AT1 and angiotensin II type 2 receptor (AT1-AT2 heteromer).
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Affiliation(s)
- Elizabeth K. M. Johnstone
- Molecular Endocrinology and Pharmacology Group, Harry Perkins Institute of Medical Research, Nedlands, WA 6009, Australia; (H.B.S.); (R.S.A.); (S.J.H.)
- Centre for Medical Research, The University of Western Australia, Crawley, WA 6009, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Canberra, NSW 2609, Australia
| | - Heng B. See
- Molecular Endocrinology and Pharmacology Group, Harry Perkins Institute of Medical Research, Nedlands, WA 6009, Australia; (H.B.S.); (R.S.A.); (S.J.H.)
- Centre for Medical Research, The University of Western Australia, Crawley, WA 6009, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Canberra, NSW 2609, Australia
| | - Rekhati S. Abhayawardana
- Molecular Endocrinology and Pharmacology Group, Harry Perkins Institute of Medical Research, Nedlands, WA 6009, Australia; (H.B.S.); (R.S.A.); (S.J.H.)
- Centre for Medical Research, The University of Western Australia, Crawley, WA 6009, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Canberra, NSW 2609, Australia
| | - Angela Song
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, St Lucia, QLD 4072, Australia; (A.S.); (K.J.R.)
| | - K. Johan Rosengren
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, St Lucia, QLD 4072, Australia; (A.S.); (K.J.R.)
| | - Stephen J. Hill
- Molecular Endocrinology and Pharmacology Group, Harry Perkins Institute of Medical Research, Nedlands, WA 6009, Australia; (H.B.S.); (R.S.A.); (S.J.H.)
- Centre for Medical Research, The University of Western Australia, Crawley, WA 6009, Australia
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham Medical School, Nottingham NG7 2UH, UK
- Centre of Membrane Proteins and Receptors, University of Nottingham, Midlands NG7 2UH, UK
| | - Kevin D. G. Pfleger
- Molecular Endocrinology and Pharmacology Group, Harry Perkins Institute of Medical Research, Nedlands, WA 6009, Australia; (H.B.S.); (R.S.A.); (S.J.H.)
- Centre for Medical Research, The University of Western Australia, Crawley, WA 6009, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Canberra, NSW 2609, Australia
- Dimerix Limited, Nedlands, WA 6009, Australia
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Hamilton AJ, Payne AD, Mocerino M, Gunosewoyo H. Imaging Cannabinoid Receptors: A Brief Collection of Covalent and Fluorescent Probes for CB1 and CB2 Receptors. Aust J Chem 2021. [DOI: 10.1071/ch21007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
There has been an expanding public interest towards the notion that modulation of the sophisticated endocannabinoid system can lead to various therapeutic benefits that are yet to be fully explored. In recent years, the drug discovery paradigm in this field has been largely based on the development of selective CB2 receptor agonists, avoiding the unwanted CB1 receptor-mediated psychoactive side effects. Mechanistically, target engagement studies are crucial for confirming the ligand–receptor interaction and the subsequent biological cascades that lead to the observed therapeutic effects. Concurrently, imaging techniques for visualisation of cannabinoid receptors are increasingly reported in the literature. Small molecule imaging tools ranging from phytocannabinoids such as tetrahydrocannabinol (THC) and cannabidiol (CBD) to the endocannabinoids as well as the purely synthetic cannabimimetics, have been explored to date with varying degrees of success. This Review will cover currently known photoactivatable, electrophilic, and fluorescent ligands for both the CB1 and CB2 receptors. Structural insights from techniques such as ligand-assisted protein structure (LAPS) and the discovery of novel allosteric modulators are significant additions for better understanding of the endocannabinoid system. There has also been a plethora of fluorescent conjugates that have been assessed for their binding to cannabinoid receptors as well as their potential for cellular imaging. More recently, bifunctional probes containing either fluorophores or electrophilic tags are becoming more prevalent in the literature. Collectively, these molecular tools are invaluable in demonstrating target engagement within the human endocannabinoid system.
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Tóth AD, Garger D, Prokop S, Soltész-Katona E, Várnai P, Balla A, Turu G, Hunyady L. A general method for quantifying ligand binding to unmodified receptors using Gaussia luciferase. J Biol Chem 2021; 296:100366. [PMID: 33545176 PMCID: PMC7950324 DOI: 10.1016/j.jbc.2021.100366] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 01/27/2021] [Accepted: 02/01/2021] [Indexed: 11/23/2022] Open
Abstract
Reliable measurement of ligand binding to cell surface receptors is of outstanding biological and pharmacological importance. Resonance energy transfer-based assays are powerful approaches to achieve this goal, but the currently available methods are hindered by the necessity of receptor tagging, which can potentially alter ligand binding properties. Therefore, we developed a tag-free system to measure ligand‒receptor interactions in live cells using the Gaussia luciferase (GLuc) as a bioluminescence resonance energy transfer donor. GLuc is as small as the commonly applied Nanoluciferase but has enhanced brightness, and its proper substrate is the frequently used coelenterazine. In our assay, bystander bioluminescence resonance energy transfer is detected between a GLuc-based extracellular surface biosensor and fluorescent ligands bound to their unmodified receptors. The broad spectrum of applications includes equilibrium and kinetic ligand binding measurements for both labeled and competitive unlabeled ligands, and the assay can be utilized for different classes of plasma membrane receptors. Furthermore, the assay is suitable for high-throughput screening, as evidenced by the identification of novel α1 adrenergic receptor ligands. Our data demonstrate that GLuc-based biosensors provide a simple, sensitive, and cost-efficient platform for drug characterization and development.
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Affiliation(s)
- András Dávid Tóth
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary; MTA-SE Laboratory of Molecular Physiology, Eötvös Loránd Research Network, Budapest, Hungary; Department of Internal Medicine and Hematology, Semmelweis University, Budapest, Hungary
| | - Dániel Garger
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Susanne Prokop
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary; Szentágothai János Doctoral School of Neuroscience, Semmelweis University, Budapest, Hungary
| | - Eszter Soltész-Katona
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary; MTA-SE Laboratory of Molecular Physiology, Eötvös Loránd Research Network, Budapest, Hungary
| | - Péter Várnai
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary; MTA-SE Laboratory of Molecular Physiology, Eötvös Loránd Research Network, Budapest, Hungary
| | - András Balla
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary; MTA-SE Laboratory of Molecular Physiology, Eötvös Loránd Research Network, Budapest, Hungary
| | - Gábor Turu
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary; MTA-SE Laboratory of Molecular Physiology, Eötvös Loránd Research Network, Budapest, Hungary
| | - László Hunyady
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary; MTA-SE Laboratory of Molecular Physiology, Eötvös Loránd Research Network, Budapest, Hungary.
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Boursier ME, Levin S, Hurst R, Ohana RF. Equilibrium and Kinetic Measurements of Ligand Binding to HiBiT-tagged GPCRs on the Surface of Living Cells. Bio Protoc 2020; 10:e3861. [PMID: 33659503 DOI: 10.21769/bioprotoc.3861] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 10/21/2020] [Accepted: 10/27/2020] [Indexed: 11/02/2022] Open
Abstract
G-protein coupled receptors (GPCRs) remain at the forefront of drug discovery efforts. Detailed assessment of features contributing to GPCR ligand engagement in a physiologically relevant environment is imperative to the development of new therapeutics with improved efficacy. Traditionally, binding properties such as affinity and kinetics were obtained using biochemical radioligand binding assays. More recently, the high specificity of resonance energy transfer has been leveraged toward the development of homogeneous cell-based proximity assays with capacity for real-time kinetic measurements. This suite of ligand binding protocols couples the specificity of bioluminescent resonance energy transfer (BRET) with the sensitivity afforded by the luminescent HiBiT peptide. The BRET format is used to quantify dynamic interactions between ligands and their cognate HiBiT-tagged GPCRs through competitive binding with fluorescent Tracers. At the same time, high affinity complementation of HiBiT with the cell impermeable LgBiT limits the bright bioluminescence donor signal to the cell surface and eliminates luminescence background from unoccupied receptors present in intracellular compartments.
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Affiliation(s)
| | - Sergiy Levin
- Promega Biosciences LLC, San Luis Obispo, California, USA
| | - Robin Hurst
- Promega Corporation, Fitchburg, Wisconsin, USA
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BRET- and fluorescence anisotropy-based assays for real-time monitoring of ligand binding to M 2 muscarinic acetylcholine receptors. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1868:118930. [PMID: 33347921 DOI: 10.1016/j.bbamcr.2020.118930] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 11/26/2020] [Accepted: 12/11/2020] [Indexed: 12/14/2022]
Abstract
BRET and fluorescence anisotropy (FA) are two fluorescence-based techniques used for the characterization of ligand binding to G protein-coupled receptors (GPCRs) and both allow monitoring of ligand binding in real time. In this study, we present the first direct comparison of BRET-based and FA-based binding assays using the human M2 muscarinic acetylcholine receptor (M2R) and two TAMRA (5-carboxytetramethylrhodamine)-labeled fluorescent ligands as a model system. The determined fluorescent ligand affinities from both assays were in good agreement with results obtained from radioligand competition binding experiments. The assays yielded real-time kinetic binding data revealing differences in the mechanism of binding for the investigated fluorescent probes. Furthermore, the investigation of various unlabeled M2R ligands yielded pharmacological profiles in accordance with earlier reported data. Taken together, this study showed that BRET- and FA-based binding assays represent valuable alternatives to radioactivity-based methods for screening purposes and for a precise characterization of binding kinetics supporting the exploration of binding mechanisms.
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New small molecule fluorescent probes for G protein-coupled receptors: valuable tools for drug discovery. Future Med Chem 2020; 13:63-90. [PMID: 33319586 DOI: 10.4155/fmc-2019-0327] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
G protein-coupled receptors (GPCRs) are essential signaling proteins and tractable therapeutic targets. To develop new drug candidates, GPCR drug discovery programs require versatile, sensitive pharmacological tools for ligand binding and compound screening. With the availability of new imaging modalities and proximity-based ligand binding technologies, fluorescent ligands offer many advantages and are increasingly being used, yet labeling small molecules remains considerably more challenging relative to peptides. Focusing on recent fluorescent small molecule studies for family A GPCRs, this review addresses some of the key challenges, synthesis approaches and structure-activity relationship considerations, and discusses advantages of using high-resolution GPCR structures to inform conjugation strategies. While no single approach guarantees successful labeling without loss of affinity or selectivity, the choice of fluorophore, linker type and site of attachment have proved to be critical factors that can significantly affect their utility in drug discovery programs, and as discussed, can sometimes lead to very unexpected results.
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Blay V, Tolani B, Ho SP, Arkin MR. High-Throughput Screening: today's biochemical and cell-based approaches. Drug Discov Today 2020; 25:1807-1821. [PMID: 32801051 DOI: 10.1016/j.drudis.2020.07.024] [Citation(s) in RCA: 83] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 07/01/2020] [Accepted: 07/30/2020] [Indexed: 12/13/2022]
Abstract
High-throughput screening (HTS) provides starting chemical matter in the adventure of developing a new drug. In this review, we survey several HTS methods used today for hit identification, organized in two main flavors: biochemical and cell-based assays. Biochemical assays discussed include fluorescence polarization and anisotropy, FRET, TR-FRET, and fluorescence lifetime analysis. Binding-based methods are also surveyed, including NMR, SPR, mass spectrometry, and DSF. On the other hand, cell-based assays discussed include viability, reporter gene, second messenger, and high-throughput microscopy assays. We devote some emphasis to high-content screening, which is becoming very popular. An advisable stage after hit discovery using phenotypic screens is target deconvolution, and we provide an overview of current chemical proteomics, in silico, and chemical genetics tools. Emphasis is made on recent CRISPR/dCas-based screens. Lastly, we illustrate some of the considerations that inform the choice of HTS methods and point to some areas with potential interest for future research.
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Affiliation(s)
- Vincent Blay
- Division of Biomaterials and Bioengineering, School of Dentistry, University of California San Francisco, San Francisco, CA 94143, USA; Department of Urology, School of Medicine, University of California San Francisco, San Francisco, CA 94143, USA.
| | - Bhairavi Tolani
- Thoracic Oncology Program, Department of Surgery, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA
| | - Sunita P Ho
- Division of Biomaterials and Bioengineering, School of Dentistry, University of California San Francisco, San Francisco, CA 94143, USA; Department of Urology, School of Medicine, University of California San Francisco, San Francisco, CA 94143, USA
| | - Michelle R Arkin
- Department of Pharmaceutical Chemistry and the Small Molecule Discovery Center, University of California, San Francisco, CA, USA.
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Grätz L, Tropmann K, Bresinsky M, Müller C, Bernhardt G, Pockes S. NanoBRET binding assay for histamine H 2 receptor ligands using live recombinant HEK293T cells. Sci Rep 2020; 10:13288. [PMID: 32764682 PMCID: PMC7414126 DOI: 10.1038/s41598-020-70332-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 07/24/2020] [Indexed: 01/12/2023] Open
Abstract
Fluorescence/luminescence-based techniques play an increasingly important role in the development of test systems for the characterization of future drug candidates, especially in terms of receptor binding in the field of G protein-coupled receptors (GPCRs). In this article, we present the establishment of a homogeneous live cell-based BRET binding assay for the histamine H2 receptor with different fluorescently labeled squaramide-type compounds synthesized in the course of this study. Py-1-labeled ligand 8 (UR-KAT478) was found to be most suitable in BRET saturation binding experiments with respect to receptor affinity (pKd = 7.35) and signal intensity. Real-time kinetic experiments showed a full association of 8 within approximately 30 min and a slow dissociation of the ligand from the receptor. Investigation of reference compounds in BRET-based competition binding with 8 yielded pKi values in agreement with radioligand binding data. This study shows that the BRET binding assay is a versatile test system for the characterization of putative new ligands at the histamine H2 receptor and represents a valuable fluorescence-based alternative to canonical binding assays.
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Affiliation(s)
- Lukas Grätz
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Katharina Tropmann
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Merlin Bresinsky
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Christoph Müller
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Günther Bernhardt
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Steffen Pockes
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany.
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40
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Gruber CG, Pegoli A, Müller C, Grätz L, She X, Keller M. Differently fluorescence-labelled dibenzodiazepinone-type muscarinic acetylcholine receptor ligands with high M 2R affinity. RSC Med Chem 2020; 11:823-832. [PMID: 33479678 PMCID: PMC7650007 DOI: 10.1039/d0md00137f] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 05/20/2020] [Indexed: 11/21/2022] Open
Abstract
A series of fluorescent dibenzodiazepinone-type muscarinic acetylcholine M2 receptor (M2R) ligands was synthesized using various fluorescent dyes (5-TAMRA, λ ex/λ em ≈ 547/576 nm; BODIPY 630/650, λ ex/λ em ≈ 625/640 nm; pyridinium dye Py-1, λ ex/λ em ≈ 611/665 nm and pyridinium dye Py-5, λ ex/λ em ≈ 465/732 nm). All fluorescent probes exhibited high M2R affinity (pK i (radioligand competition binding): 8.75-9.62, pK d (flow cytometry): 8.36-9.19), a very low preference for the M2R over the M1 and M4 receptors and moderate to pronounced M2R selectivity compared to the M3 and M5 receptors. The presented fluorescent ligands are considered useful molecular tools for future studies using methods such as fluorescence anisotropy and BRET based MR binding assays.
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Affiliation(s)
- Corinna G Gruber
- Institute of Pharmacy , Faculty of Chemistry and Pharmacy , University of Regensburg , Universitätsstrasse 31 , D-93053 Regensburg , Germany .
| | - Andrea Pegoli
- Institute of Pharmacy , Faculty of Chemistry and Pharmacy , University of Regensburg , Universitätsstrasse 31 , D-93053 Regensburg , Germany .
| | - Christoph Müller
- Institute of Pharmacy , Faculty of Chemistry and Pharmacy , University of Regensburg , Universitätsstrasse 31 , D-93053 Regensburg , Germany .
| | - Lukas Grätz
- Institute of Pharmacy , Faculty of Chemistry and Pharmacy , University of Regensburg , Universitätsstrasse 31 , D-93053 Regensburg , Germany .
| | - Xueke She
- Institute of Pharmacy , Faculty of Chemistry and Pharmacy , University of Regensburg , Universitätsstrasse 31 , D-93053 Regensburg , Germany .
| | - Max Keller
- Institute of Pharmacy , Faculty of Chemistry and Pharmacy , University of Regensburg , Universitätsstrasse 31 , D-93053 Regensburg , Germany .
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41
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Ray M, Nagai K, Kihara Y, Kussrow A, Kammer MN, Frantz A, Bornhop DJ, Chun J. Unlabeled lysophosphatidic acid receptor binding in free solution as determined by a compensated interferometric reader. J Lipid Res 2020; 61:1244-1251. [PMID: 32513900 PMCID: PMC7397748 DOI: 10.1194/jlr.d120000880] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 06/01/2020] [Indexed: 12/11/2022] Open
Abstract
Native interactions between lysophospholipids (LPs) and their cognate LP receptors are difficult to measure because of lipophilicity and/or the adhesive properties of lipids, which contribute to high levels of nonspecific binding in cell membrane preparations. Here, we report development of a free-solution assay (FSA) where label-free LPs bind to their cognate G protein-coupled receptors (GPCRs), combined with a recently reported compensated interferometric reader (CIR) to quantify native binding interactions between receptors and ligands. As a test case, the binding parameters between lysophosphatidic acid (LPA) receptor 1 (LPA1; one of six cognate LPA GPCRs) and LPA were determined. FSA-CIR detected specific binding through the simultaneous real-time comparison of bound versus unbound species by measuring the change in the solution dipole moment produced by binding-induced conformational and/or hydration changes. FSA-CIR identified KD values for chemically distinct LPA species binding to human LPA1 and required only a few nanograms of protein: 1-oleoyl (18:1; KD = 2.08 ± 1.32 nM), 1-linoleoyl (18:2; KD = 2.83 ± 1.64 nM), 1-arachidonoyl (20:4; KD = 2.59 ± 0.481 nM), and 1-palmitoyl (16:0; KD = 1.69 ± 0.1 nM) LPA. These KD values compared favorably to those obtained using the previous generation back-scattering interferometry system, a chip-based technique with low-throughput and temperature sensitivity. In conclusion, FSA-CIR offers a new increased-throughput approach to assess quantitatively label-free lipid ligand-receptor binding, including nonactivating antagonist binding, under near-native conditions.
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Affiliation(s)
- Manisha Ray
- Degenerative Disease Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037
| | - Kazufumi Nagai
- Degenerative Disease Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037
| | - Yasuyuki Kihara
- Degenerative Disease Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037
| | - Amanda Kussrow
- Department of Chemistry and Vanderbilt Institute for Chemical Biology, Vanderbilt University, Nashville, TN 37235
| | - Michael N Kammer
- Department of Chemistry and Vanderbilt Institute for Chemical Biology, Vanderbilt University, Nashville, TN 37235
| | - Aaron Frantz
- Degenerative Disease Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037.,Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, CA 92037
| | - Darryl J Bornhop
- Department of Chemistry and Vanderbilt Institute for Chemical Biology, Vanderbilt University, Nashville, TN 37235
| | - Jerold Chun
- Degenerative Disease Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037
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She X, Pegoli A, Gruber CG, Wifling D, Carpenter J, Hübner H, Chen M, Wan J, Bernhardt G, Gmeiner P, Holliday ND, Keller M. Red-Emitting Dibenzodiazepinone Derivatives as Fluorescent Dualsteric Probes for the Muscarinic Acetylcholine M2 Receptor. J Med Chem 2020; 63:4133-4154. [PMID: 32233403 DOI: 10.1021/acs.jmedchem.9b02172] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Xueke She
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Andrea Pegoli
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Corinna G. Gruber
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - David Wifling
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Jessica Carpenter
- School of Life Sciences, University of Nottingham, Queen’s Medical Centre, Derby Road, Nottingham NG7 2UH, U.K
| | - Harald Hübner
- Department of Chemistry and Pharmacy, Medicinal Chemistry, Friedrich Alexander University, Nikolaus-Fiebiger-Straße 10, D-91058 Erlangen, Germany
| | - Mengya Chen
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Jianfei Wan
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Günther Bernhardt
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Peter Gmeiner
- Department of Chemistry and Pharmacy, Medicinal Chemistry, Friedrich Alexander University, Nikolaus-Fiebiger-Straße 10, D-91058 Erlangen, Germany
| | - Nicholas D. Holliday
- School of Life Sciences, University of Nottingham, Queen’s Medical Centre, Derby Road, Nottingham NG7 2UH, U.K
| | - Max Keller
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
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Duan X, Chen Z, Tang S, Ge M, Wei H, Guan Y, Zhao G. A Strategy Employing a TF-Splinting Duplex Nanoswitch to Achieve Single-Step, Enzyme-Free, Signal-On Detection of l-Tryptophan. ACS Sens 2020; 5:837-844. [PMID: 32096406 DOI: 10.1021/acssensors.0c00002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Transcription factor (TF)-based metabolite detection mainly depends on TF-regulated gene expression in cells. From TF activation to gene transcription and translation, the signal travels a relatively long way before it is received. Here, we propose a TF-splinting duplex DNA nanoswitch to detect metabolites. We show its feasibility using tryptophan repressor (TrpR) to detect l-tryptophan as a model. The assay has been optimized and characterized after obtaining a proof of concept, and the detection of l-tryptophan in complex biological samples is feasible. Unlike an equivalent gene expression approach, the whole process is a single-step, enzyme-free, and signal-on method. It can be completed within 20 min. This proposed TF-splinting duplex has the potential to be applied to the quick and convenient detection of other metabolites or even TFs.
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Affiliation(s)
- Xuying Duan
- Department of Biochemistry and Molecular Biology, School of Life Sciences, China Medical University, Shenyang, Liaoning 110001, China
| | - Ziwei Chen
- Department of Biochemistry and Molecular Biology, School of Life Sciences, China Medical University, Shenyang, Liaoning 110001, China
| | - Suming Tang
- Department of Biochemistry and Molecular Biology, School of Life Sciences, China Medical University, Shenyang, Liaoning 110001, China
| | - Meiqiong Ge
- Department of Biochemistry and Molecular Biology, School of Life Sciences, China Medical University, Shenyang, Liaoning 110001, China
| | - Hua Wei
- Department of Biochemistry and Molecular Biology, School of Life Sciences, China Medical University, Shenyang, Liaoning 110001, China
- Animal Science and Veterinary Medicine College, Shenyang Agricultural University, Shenyang, Liaoning 110866, China
| | - Yifu Guan
- Department of Biochemistry and Molecular Biology, School of Life Sciences, China Medical University, Shenyang, Liaoning 110001, China
| | - Guojie Zhao
- Department of Biochemistry and Molecular Biology, School of Life Sciences, China Medical University, Shenyang, Liaoning 110001, China
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Boursier ME, Levin S, Zimmerman K, Machleidt T, Hurst R, Butler BL, Eggers CT, Kirkland TA, Wood KV, Friedman Ohana R. The luminescent HiBiT peptide enables selective quantitation of G protein-coupled receptor ligand engagement and internalization in living cells. J Biol Chem 2020; 295:5124-5135. [PMID: 32107310 DOI: 10.1074/jbc.ra119.011952] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 02/18/2020] [Indexed: 01/19/2023] Open
Abstract
G protein-coupled receptors (GPCRs) are prominent targets to new therapeutics for a range of diseases. Comprehensive assessments of their cellular interactions with bioactive compounds, particularly in a kinetic format, are imperative to the development of drugs with improved efficacy. Hence, we developed complementary cellular assays that enable equilibrium and real-time analyses of GPCR ligand engagement and consequent activation, measured as receptor internalization. These assays utilize GPCRs genetically fused to an N-terminal HiBiT peptide (1.3 kDa), which produces bright luminescence upon high-affinity complementation with LgBiT, an 18-kDa subunit derived from NanoLuc. The cell impermeability of LgBiT limits signal detection to the cell surface and enables measurements of ligand-induced internalization through changes in cell-surface receptor density. In addition, bioluminescent resonance energy transfer is used to quantify dynamic interactions between ligands and their cognate HiBiT-tagged GPCRs through competitive binding with fluorescent tracers. The sensitivity and dynamic range of these assays benefit from the specificity of bioluminescent resonance energy transfer and the high signal intensity of HiBiT/LgBiT without background luminescence from receptors present in intracellular compartments. These features allow analyses of challenging interactions having low selectivity or affinity and enable studies using endogenously tagged receptors. Using the β-adrenergic receptor family as a model, we demonstrate the versatility of these assays by utilizing the same HiBiT construct in analyses of multiple aspects of GPCR pharmacology. We anticipate that this combination of target engagement and proximal functional readout will prove useful to the study of other GPCR families and the development of new therapeutics.
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Affiliation(s)
| | - Sergiy Levin
- Promega Biosciences LLC, San Luis Obispo, California 93401
| | | | | | - Robin Hurst
- Promega Corporation, Fitchburg, Wisconsin 53711
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45
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Soave M, Briddon SJ, Hill SJ, Stoddart LA. Fluorescent ligands: Bringing light to emerging GPCR paradigms. Br J Pharmacol 2020; 177:978-991. [PMID: 31877233 DOI: 10.1111/bph.14953] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 11/19/2019] [Accepted: 12/05/2019] [Indexed: 01/07/2023] Open
Abstract
In recent years, several novel aspects of GPCR pharmacology have been described, which are thought to play a role in determining the in vivo efficacy of a compound. Fluorescent ligands have been used to study many of these, which have also required the development of new experimental approaches. Fluorescent ligands offer the potential to use the same fluorescent probe to perform a broad range of experiments, from single-molecule microscopy to in vivo BRET. This review provides an overview of the in vitro use of fluorescent ligands in further understanding emerging pharmacological paradigms within the GPCR field, including ligand-binding kinetics, allosterism and intracellular signalling, along with the use of fluorescent ligands to study physiologically relevant therapeutic agents.
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Affiliation(s)
- Mark Soave
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Stephen J Briddon
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Stephen J Hill
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Leigh A Stoddart
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
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46
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Keller M, Mahuroof SA, Hong Yee V, Carpenter J, Schindler L, Littmann T, Pegoli A, Hübner H, Bernhardt G, Gmeiner P, Holliday ND. Fluorescence Labeling of Neurotensin(8-13) via Arginine Residues Gives Molecular Tools with High Receptor Affinity. ACS Med Chem Lett 2020; 11:16-22. [PMID: 31938457 PMCID: PMC6956362 DOI: 10.1021/acsmedchemlett.9b00462] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Accepted: 11/19/2019] [Indexed: 02/07/2023] Open
Abstract
Fluorescence-labeled receptor ligands have emerged as valuable molecular tools, being indispensable for studying receptor-ligand interactions by fluorescence-based techniques such as high-content imaging, fluorescence microscopy, and fluorescence polarization. Through application of a new labeling strategy for peptides, a series of fluorescent neurotensin(8-13) derivatives was synthesized by attaching red-emitting fluorophores (indolinium- and pyridinium-type cyanine dyes) to carbamoylated arginine residues in neurotensin(8-13) analogues, yielding fluorescent probes with high NTS1R affinity (pK i values: 8.15-9.12) and potency (pEC50 values (Ca2+ mobilization): 8.23-9.43). Selected fluorescent ligands were investigated by flow cytometry and high-content imaging (saturation binding, kinetic studies, and competition binding) as well as by confocal microscopy using intact CHO-hNTS1R cells. The study demonstrates the applicability of the fluorescent probes as molecular tools to obtain, for example, information about the localization of receptors in cells and to determine binding affinities of nonlabeled ligands.
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Affiliation(s)
- Max Keller
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Shahani A. Mahuroof
- School of Life Sciences, University of Nottingham, Queen’s Medical Centre, Nottingham NG7 2UH, United Kingdom
| | - Vivyanne Hong Yee
- School of Life Sciences, University of Nottingham, Queen’s Medical Centre, Nottingham NG7 2UH, United Kingdom
| | - Jessica Carpenter
- School of Life Sciences, University of Nottingham, Queen’s Medical Centre, Nottingham NG7 2UH, United Kingdom
| | - Lisa Schindler
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Timo Littmann
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Andrea Pegoli
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Harald Hübner
- Department of Chemistry and Pharmacy, Medicinal Chemistry, Friedrich Alexander University, Nikolaus-Fiebiger-Straße 10, D-91058 Erlangen, Germany
| | - Günther Bernhardt
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Peter Gmeiner
- Department of Chemistry and Pharmacy, Medicinal Chemistry, Friedrich Alexander University, Nikolaus-Fiebiger-Straße 10, D-91058 Erlangen, Germany
| | - Nicholas D. Holliday
- School of Life Sciences, University of Nottingham, Queen’s Medical Centre, Nottingham NG7 2UH, United Kingdom
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47
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Comeo E, Kindon ND, Soave M, Stoddart LA, Kilpatrick LE, Scammells PJ, Hill SJ, Kellam B. Subtype-Selective Fluorescent Ligands as Pharmacological Research Tools for the Human Adenosine A 2A Receptor. J Med Chem 2020; 63:2656-2672. [PMID: 31887252 DOI: 10.1021/acs.jmedchem.9b01856] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Among class A G protein-coupled receptors (GPCR), the human adenosine A2A receptor (hA2AAR) remains an attractive drug target. However, translation of A2AAR ligands into the clinic has proved challenging and an improved understanding of A2AAR pharmacology could promote development of more efficacious therapies. Subtype-selective fluorescent probes would allow detailed real-time pharmacological investigations both in vitro and in vivo. In the present study, two families of fluorescent probes were designed around the known hA2AAR selective antagonist preladenant (SCH 420814). Both families of fluorescent antagonists retained affinity at the hA2AAR, selectivity over all other adenosine receptor subtypes and allowed clear visualization of specific receptor localization through confocal imaging. Furthermore, the Alexa Fluor 647-labeled conjugate allowed measurement of ligand binding affinities of unlabeled hA2AAR antagonists using a bioluminescence resonance energy transfer (NanoBRET) assay. The fluorescent ligands developed here can therefore be applied to a range of fluorescence-based techniques to further interrogate hA2AAR pharmacology and signaling.
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Affiliation(s)
- Eleonora Comeo
- Division of Biomolecular Sciences and Medicinal Chemistry, School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham NG7 2RD, U.K.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands NG7 2UH, U.K.,Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052 Australia
| | - Nicholas D Kindon
- Division of Biomolecular Sciences and Medicinal Chemistry, School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham NG7 2RD, U.K.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands NG7 2UH, U.K
| | - Mark Soave
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, U.K.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands NG7 2UH, U.K
| | - Leigh A Stoddart
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, U.K.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands NG7 2UH, U.K
| | - Laura E Kilpatrick
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, U.K.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands NG7 2UH, U.K
| | - Peter J Scammells
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052 Australia
| | - Stephen J Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, U.K.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands NG7 2UH, U.K
| | - Barrie Kellam
- Division of Biomolecular Sciences and Medicinal Chemistry, School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham NG7 2RD, U.K.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands NG7 2UH, U.K
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Chemical Probes for the Adenosine Receptors. Pharmaceuticals (Basel) 2019; 12:ph12040168. [PMID: 31726680 PMCID: PMC6958474 DOI: 10.3390/ph12040168] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 11/04/2019] [Accepted: 11/07/2019] [Indexed: 12/21/2022] Open
Abstract
Research on the adenosine receptors has been supported by the continuous discovery of new chemical probes characterized by more and more affinity and selectivity for the single adenosine receptor subtypes (A1, A2A, A2B and A3 adenosine receptors). Furthermore, the development of new techniques for the detection of G protein-coupled receptors (GPCR) requires new specific probes. In fact, if in the past radioligands were the most important GPCR probes for detection, compound screening and diagnostic purposes, nowadays, increasing importance is given to fluorescent and covalent ligands. In fact, advances in techniques such as fluorescence resonance energy transfer (FRET) and fluorescent polarization, as well as new applications in flow cytometry and different fluorescence-based microscopic techniques, are at the origin of the extensive research of new fluorescent ligands for these receptors. The resurgence of covalent ligands is due in part to a change in the common thinking in the medicinal chemistry community that a covalent drug is necessarily more toxic than a reversible one, and in part to the useful application of covalent ligands in GPCR structural biology. In this review, an updated collection of available chemical probes targeting adenosine receptors is reported.
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Gabriel J, Höfner G, Wanner KT. A Library Screening Strategy Combining the Concepts of MS Binding Assays and Affinity Selection Mass Spectrometry. Front Chem 2019; 7:665. [PMID: 31637233 PMCID: PMC6787468 DOI: 10.3389/fchem.2019.00665] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 09/18/2019] [Indexed: 01/16/2023] Open
Abstract
The primary objective of early drug development is to identify hits and leads for a target of interest. To achieve this aim, rapid, and reliable screening techniques for a huge number of compounds are needed. Mass spectrometry based binding assays (MS Binding Assays) represent a well-established technique for library screening based on competitive binding experiments revealing active sublibraries due to reduced binding of a reporter ligand and following hit identification for active libraries by deconvolution in further competitive binding experiments. In the present study, we combined the concepts of MS Binding Assays and affinity selection mass spectrometry (ASMS) to improve the efficiency of the hit identification step. In that case, only a single competitive binding experiment is performed that is in the first step analyzed for reduced binding of the reporter ligand and—only if a sublibrary is active—additionally for specific binding of individual library components. Subsequently, affinities of identified hits as well as activities of reduced sublibraries (i.e., all sublibrary components without hit) are assessed in additional competitive binding experiments. We exemplified this screening concept for the identification of ligands addressing the most widespread GABA transporter subtype in the brain (GAT1) studying in the beginning a library composed of 128 and further on a library of 1,280 well-characterized GAT1 inhibitors, drug substances, and pharmacological tool compounds. Determination of sublibraries' activities was done by quantification of bound NO711 as reporter ligand and hit identification for the active ones achieved in a further LC-ESI-MS/MS run in the multiple reaction monitoring mode enabling detection of all sublibrary components followed by hit verification and investigation of reduced sublibraries in further competitive binding experiments. In this way, we could demonstrate that all GAT1 inhibitors reducing reporter ligand binding below 50% at a concentration of 1 μM are detected reliably without generation of false positive or false negative hits. As the described strategy is apart from its reliability also highly efficient, it can be assumed to become a valuable tool in early drug research, especially for membrane integrated drug targets that are often posing problems in established screening techniques.
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Affiliation(s)
- Jürgen Gabriel
- Department of Pharmacy, Faculty of Chemistry and Pharmacy, Ludwig Maximilian University München, Munich, Germany
| | - Georg Höfner
- Department of Pharmacy, Faculty of Chemistry and Pharmacy, Ludwig Maximilian University München, Munich, Germany
| | - Klaus T Wanner
- Department of Pharmacy, Faculty of Chemistry and Pharmacy, Ludwig Maximilian University München, Munich, Germany
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50
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Wolfe AJ, Parella KJ, Movileanu L. High-Throughput Screening of Protein-Detergent Complexes Using Fluorescence Polarization Spectroscopy. ACTA ACUST UNITED AC 2019; 97:e96. [PMID: 31517448 DOI: 10.1002/cpps.96] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This article provides detailed protocols for a high-throughput fluorescence polarization (FP) spectroscopy approach to disentangle the interactions of membrane proteins with solubilizing detergents. Existing techniques for examining the membrane protein-detergent complex (PDC) interactions are low throughput and require high amounts of proteins. Here, we describe a 96-well analytical approach, which facilitates a scalable analysis of the PDC interactions at low-nanomolar concentrations of membrane proteins in native solutions. At detergent concentrations much greater than the equilibrium dissociation constant of the PDC, Kd , the FP anisotropy reaches a saturated value, so it is independent of the detergent concentration. On the contrary, at detergent concentrations comparable with or lower than the Kd , the FP anisotropy readout undergoes a time-dependent decrease, exhibiting a sensitive and specific detergent-dissociation signature. Our approach can also be used for determining the kinetic rate constants of association and dissociation. With further development, these protocols might be used in various arenas of membrane protein research that pertain to extraction, solubilization, and stabilization. © 2019 by John Wiley & Sons, Inc.
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Affiliation(s)
- Aaron J Wolfe
- Ichor Therapeutics, Inc., LaFayette, New York.,Department of Chemistry, State University of New York College of Environmental Science and Forestry, Syracuse, New York
| | - Kyle J Parella
- Ichor Therapeutics, Inc., LaFayette, New York.,Department of Chemistry, State University of New York College of Environmental Science and Forestry, Syracuse, New York
| | - Liviu Movileanu
- Department of Physics, Syracuse University, Syracuse, New York.,Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York
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