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Tropmann K, Bresinsky M, Forster L, Mönnich D, Buschauer A, Wittmann HJ, Hübner H, Gmeiner P, Pockes S, Strasser A. Abolishing Dopamine D 2long/D 3 Receptor Affinity of Subtype-Selective Carbamoylguanidine-Type Histamine H 2 Receptor Agonists. J Med Chem 2021; 64:8684-8709. [PMID: 34110814 DOI: 10.1021/acs.jmedchem.1c00692] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
3-(2-Amino-4-methylthiazol-5-yl)propyl-substituted carbamoylguanidines are potent, subtype-selective histamine H2 receptor (H2R) agonists, but their applicability as pharmacological tools to elucidate the largely unknown H2R functions in the central nervous system (CNS) is compromised by their concomitant high affinity toward dopamine D2-like receptors (especially to the D3R). To improve the selectivity, a series of novel carbamoylguanidine-type ligands containing various heterocycles, spacers, and side residues were rationally designed, synthesized, and tested in binding and/or functional assays at H1-4 and D2long/3 receptors. This study revealed a couple of selective candidates (among others 31 and 47), and the most promising ones were screened at several off-target receptors, showing good selectivities. Docking studies suggest that the amino acid residues (3.28, 3.32, E2.49, E2.51, 5.42, and 7.35) are responsible for the different affinities at the H2- and D2long/3-receptors. These results provide a solid base for the exploration of the H2R functions in the brain in further studies.
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Affiliation(s)
- Katharina Tropmann
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Merlin Bresinsky
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Lisa Forster
- 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
| | - Armin Buschauer
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Hans-Joachim Wittmann
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Harald Hübner
- Department of Chemistry and Pharmacy, Medicinal Chemistry, Friedrich-Alexander-University of Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Peter Gmeiner
- Department of Chemistry and Pharmacy, Medicinal Chemistry, Friedrich-Alexander-University of Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Steffen Pockes
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany.,Department of Neurology, University of Minnesota, Minneapolis, Minnesota 55455, United States.,Department of Medicinal Chemistry, Institute for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Andrea Strasser
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
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Grätz L, Tropmann K, Bresinsky M, Müller C, Bernhardt G, Pockes S. Author Correction: NanoBRET binding assay for histamine H 2 receptor ligands using live recombinant HEK293T cells. Sci Rep 2021; 11:12444. [PMID: 34103640 PMCID: PMC8187643 DOI: 10.1038/s41598-021-91782-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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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Biselli S, Bresinsky M, Tropmann K, Forster L, Honisch C, Buschauer A, Bernhardt G, Pockes S. Pharmacological characterization of a new series of carbamoylguanidines reveals potent agonism at the H 2R and D 3R. Eur J Med Chem 2021; 214:113190. [PMID: 33548637 DOI: 10.1016/j.ejmech.2021.113190] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/31/2020] [Accepted: 01/08/2021] [Indexed: 12/12/2022]
Abstract
Even today, the role of the histamine H2 receptor (H2R) in the central nervous system (CNS) is widely unknown. In previous research, many dimeric, high-affinity and subtype-selective carbamoylguanidine-type ligands such as UR-NK22 (5, pKi = 8.07) were reported as H2R agonists. However, their applicability to the study of the H2R in the CNS is compromised by their molecular and pharmacokinetic properties, such as high molecular weight and, consequently, a limited bioavailability. To address the need for more drug-like H2R agonists with high affinity, we synthesized a series of monomeric (thio)carbamoylguanidine-type ligands containing various spacers and side-chain moieties. This structural simplification resulted in potent (partial) agonists (guinea pig right atrium, [35S]GTPγS and β-arrestin2 recruitment assays) with human (h) H2R affinities in the one-digit nanomolar range (pKi (139, UR-KAT523): 8.35; pKi (157, UR-MB-69): 8.69). Most of the compounds presented here exhibited an excellent selectivity profile towards the hH2R, e.g. 157 being at least 3800-fold selective within the histamine receptor family. The structural similarities of our monomeric ligands to pramipexole (6), a dopamine receptor agonist, suggested an investigation of the binding behavior at those receptors. The target compounds were (partial) agonists with moderate affinity at the hD2longR and agonists with high affinity at the hD3R (e.g. pKi (139, UR-KAT523): 7.80; pKi (157, UR-MB-69): 8.06). In summary, we developed a series of novel, more drug-like H2R and D3R agonists for the application in recombinant systems in which either the H2R or the D3R is solely expressed. Furthermore, our ligands are promising lead compounds in the development of selective H2R agonists for future in vivo studies or experiments utilizing primary tissue to unravel the role and function of the H2R in the CNS.
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Affiliation(s)
- Sabrina Biselli
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053, Regensburg, Germany; Agrolab Labor GmbH, 84079, Bruckberg, Germany
| | - Merlin Bresinsky
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053, Regensburg, Germany
| | - Katharina Tropmann
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053, Regensburg, Germany
| | - Lisa Forster
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053, Regensburg, Germany
| | - Claudia Honisch
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053, Regensburg, Germany; Institute of Biomolecular Chemistry - National Research Council (ICB-CNR), Padua Unit Via F. Marzolo, 1, 35131, Padova, Italy
| | - Armin Buschauer
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053, Regensburg, Germany
| | - Günther Bernhardt
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053, Regensburg, Germany
| | - Steffen Pockes
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053, Regensburg, Germany; Department of Neurology, University of Minnesota, Minneapolis, MN, 55455, USA; Department of Medicinal Chemistry, Institute for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, MN, 55414, USA.
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Höring C, Seibel U, Tropmann K, Grätz L, Mönnich D, Pitzl S, Bernhardt G, Pockes S, Strasser A. A Dynamic, Split-Luciferase-Based Mini-G Protein Sensor to Functionally Characterize Ligands at All Four Histamine Receptor Subtypes. Int J Mol Sci 2020; 21:ijms21228440. [PMID: 33182741 PMCID: PMC7698210 DOI: 10.3390/ijms21228440] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 11/06/2020] [Accepted: 11/08/2020] [Indexed: 02/06/2023] Open
Abstract
In drug discovery, assays with proximal readout are of great importance to study target-specific effects of potential drug candidates. In the field of G protein-coupled receptors (GPCRs), the determination of GPCR-G protein interactions and G protein activation by means of radiolabeled GTP analogs ([35S]GTPγS, [γ-32P]GTP) has widely been used for this purpose. Since we were repeatedly faced with insufficient quality of radiolabeled nucleotides, there was a requirement to implement a novel proximal functional assay for the routine characterization of putative histamine receptor ligands. We applied the split-NanoLuc to the four histamine receptor subtypes (H1R, H2R, H3R, H4R) and recently engineered minimal G (mini-G) proteins. Using this method, the functional response upon receptor activation was monitored in real-time and the four mini-G sensors were evaluated by investigating selected standard (inverse) agonists and antagonists. All potencies and efficacies of the studied ligands were in concordance with literature data. Further, we demonstrated a significant positive correlation of the signal amplitude and the mini-G protein expression level in the case of the H2R, but not for the H1R or the H3R. The pEC50 values of histamine obtained under different mini-G expression levels were consistent. Moreover, we obtained excellent dynamic ranges (Z’ factor) and the signal spans were improved for all receptor subtypes in comparison to the previously performed [35S]GTPγS binding assay.
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Affiliation(s)
- Carina Höring
- Correspondence: (C.H.); , (A.S.); Tel.: +49-941-943-4748 (C.H.); +49-941-943-4821 (A.S.)
| | | | | | | | | | | | | | | | - Andrea Strasser
- Correspondence: (C.H.); , (A.S.); Tel.: +49-941-943-4748 (C.H.); +49-941-943-4821 (A.S.)
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Tropmann K, Höring C, Plank N, Pockes S. Discovery of a G Protein-Biased Radioligand for the Histamine H2 Receptor with Reversible Binding Properties. J Med Chem 2020; 63:13090-13102. [DOI: 10.1021/acs.jmedchem.0c01494] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Katharina Tropmann
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Carina Höring
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Nicole Plank
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Steffen Pockes
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
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Biselli S, Alencastre I, Tropmann K, Erdmann D, Chen M, Littmann T, Maia AF, Gomez-Lazaro M, Tanaka M, Ozawa T, Keller M, Lamghari M, Buschauer A, Bernhardt G. Fluorescent H 2 Receptor Squaramide-Type Antagonists: Synthesis, Characterization, and Applications. ACS Med Chem Lett 2020; 11:1521-1528. [PMID: 32832018 DOI: 10.1021/acsmedchemlett.0c00033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 07/20/2020] [Indexed: 02/08/2023] Open
Abstract
Fluorescence labeled ligands have been gaining importance as molecular tools, enabling receptor-ligand-binding studies by various fluorescence-based techniques. Aiming at red-emitting fluorescent ligands for the hH2R, a series of squaramides labeled with pyridinium or cyanine fluorophores (19-27) was synthesized and characterized. The highest hH2R affinities in radioligand competition binding assays were obtained in the case of pyridinium labeled antagonists 19-21 (pK i: 7.71-7.76) and cyanine labeled antagonists 23 and 25 (pK i: 7.67, 7.11). These fluorescent ligands proved to be useful tools for binding studies (saturation and competition binding as well as kinetic experiments), using confocal microscopy, flow cytometry, and high content imaging. Saturation binding experiments revealed pK d values comparable to the pK i values. The fluorescent probes 21, 23, and 25 could be used to localize H2 receptors in HEK cells and to determine the binding affinities of unlabeled compounds.
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Affiliation(s)
- Sabrina Biselli
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Inês Alencastre
- i3S - Instituto de Investigação e Inovação em Saúde da Universidade do Porto, 4200-135 Porto, Portugal
- INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
| | - Katharina Tropmann
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Daniela Erdmann
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Mengya Chen
- 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
| | - André F. Maia
- i3S - Instituto de Investigação e Inovação em Saúde da Universidade do Porto, 4200-135 Porto, Portugal
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Maria Gomez-Lazaro
- i3S - Instituto de Investigação e Inovação em Saúde da Universidade do Porto, 4200-135 Porto, Portugal
- INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
| | - Miho Tanaka
- Department of Chemistry, School of Science, University of Tokyo, 7-3-1 Bunkyo-ku, Hongo, Tokyo 113-0033, Japan
| | - Takeaki Ozawa
- Department of Chemistry, School of Science, University of Tokyo, 7-3-1 Bunkyo-ku, Hongo, Tokyo 113-0033, Japan
| | - Max Keller
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Meriem Lamghari
- i3S - Instituto de Investigação e Inovação em Saúde da Universidade do Porto, 4200-135 Porto, Portugal
- INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
| | - Armin Buschauer
- 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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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] [What about the content of this article? (0)] [Affiliation(s)] [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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