Irreversible Antagonists for the Adenosine A<sub>2B</sub> Receptor
Blockade of the adenosine A<sub>2B</sub> receptor (A<sub>2B</sub>AR) represents a potential novel strategy for the immunotherapy of cancer. In the present study, we designed, synthesized, and characterized irreversible A<sub>2B</sub>AR antagonists based on an 8-&l...
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| Format: | Article |
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MDPI AG
2022-06-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/27/12/3792 |
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| author | Ahmed Temirak Jonathan G. Schlegel Jan H. Voss Victoria J. Vaaßen Christin Vielmuth Tobias Claff Christa E. Müller |
| author_facet | Ahmed Temirak Jonathan G. Schlegel Jan H. Voss Victoria J. Vaaßen Christin Vielmuth Tobias Claff Christa E. Müller |
| author_sort | Ahmed Temirak |
| collection | DOAJ |
| description | Blockade of the adenosine A<sub>2B</sub> receptor (A<sub>2B</sub>AR) represents a potential novel strategy for the immunotherapy of cancer. In the present study, we designed, synthesized, and characterized irreversible A<sub>2B</sub>AR antagonists based on an 8-<i>p</i>-sulfophenylxanthine scaffold. Irreversible binding was confirmed in radioligand binding and bioluminescence resonance energy transfer(BRET)-based Gα<sub>15</sub> protein activation assays by performing ligand wash-out and kinetic experiments. <i>p</i>-(1-Propylxanthin-8-yl)benzene sulfonyl fluoride (<b>6a</b>, PSB-21500) was the most potent and selective irreversible A<sub>2B</sub>AR antagonist of the present series with an apparent K<sub>i</sub> value of 10.6 nM at the human A<sub>2B</sub>AR and >38-fold selectivity versus the other AR subtypes. The corresponding 3-cyclopropyl-substituted xanthine derivative <b>6c</b> (PSB-21502) was similarly potent, but was non-selective versus A<sub>1</sub>- and A<sub>2A</sub>ARs. Attachment of a reactive sulfonyl fluoride group to an elongated xanthine 8-substituent (<b>12</b>, K<sub>i</sub> 7.37 nM) resulted in a potent, selective, reversibly binding antagonist. Based on previous docking studies, the lysine residue K269<sup>7.32</sup> was proposed to react with the covalent antagonists. However, the mutant K269L behaved similarly to the wildtype A<sub>2B</sub>AR, indicating that <b>6a</b> and related irreversible A<sub>2B</sub>AR antagonists do not interact with K269<sup>7.32</sup>. The new irreversible A<sub>2B</sub>AR antagonists will be useful tools and have the potential to be further developed as therapeutic drugs. |
| first_indexed | 2024-03-09T22:56:34Z |
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| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-09T22:56:34Z |
| publishDate | 2022-06-01 |
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| spelling | doaj.art-d0d8be1988af4d15968751ab4b7f458a2023-11-23T18:11:22ZengMDPI AGMolecules1420-30492022-06-012712379210.3390/molecules27123792Irreversible Antagonists for the Adenosine A<sub>2B</sub> ReceptorAhmed Temirak0Jonathan G. Schlegel1Jan H. Voss2Victoria J. Vaaßen3Christin Vielmuth4Tobias Claff5Christa E. Müller6PharmaCenter Bonn & Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, 53121 Bonn, GermanyPharmaCenter Bonn & Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, 53121 Bonn, GermanyPharmaCenter Bonn & Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, 53121 Bonn, GermanyPharmaCenter Bonn & Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, 53121 Bonn, GermanyPharmaCenter Bonn & Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, 53121 Bonn, GermanyPharmaCenter Bonn & Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, 53121 Bonn, GermanyPharmaCenter Bonn & Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, 53121 Bonn, GermanyBlockade of the adenosine A<sub>2B</sub> receptor (A<sub>2B</sub>AR) represents a potential novel strategy for the immunotherapy of cancer. In the present study, we designed, synthesized, and characterized irreversible A<sub>2B</sub>AR antagonists based on an 8-<i>p</i>-sulfophenylxanthine scaffold. Irreversible binding was confirmed in radioligand binding and bioluminescence resonance energy transfer(BRET)-based Gα<sub>15</sub> protein activation assays by performing ligand wash-out and kinetic experiments. <i>p</i>-(1-Propylxanthin-8-yl)benzene sulfonyl fluoride (<b>6a</b>, PSB-21500) was the most potent and selective irreversible A<sub>2B</sub>AR antagonist of the present series with an apparent K<sub>i</sub> value of 10.6 nM at the human A<sub>2B</sub>AR and >38-fold selectivity versus the other AR subtypes. The corresponding 3-cyclopropyl-substituted xanthine derivative <b>6c</b> (PSB-21502) was similarly potent, but was non-selective versus A<sub>1</sub>- and A<sub>2A</sub>ARs. Attachment of a reactive sulfonyl fluoride group to an elongated xanthine 8-substituent (<b>12</b>, K<sub>i</sub> 7.37 nM) resulted in a potent, selective, reversibly binding antagonist. Based on previous docking studies, the lysine residue K269<sup>7.32</sup> was proposed to react with the covalent antagonists. However, the mutant K269L behaved similarly to the wildtype A<sub>2B</sub>AR, indicating that <b>6a</b> and related irreversible A<sub>2B</sub>AR antagonists do not interact with K269<sup>7.32</sup>. The new irreversible A<sub>2B</sub>AR antagonists will be useful tools and have the potential to be further developed as therapeutic drugs.https://www.mdpi.com/1420-3049/27/12/3792adenosineBRET assaycovalent bindingGα<sub>15</sub>G protein activationG protein-coupled receptor |
| spellingShingle | Ahmed Temirak Jonathan G. Schlegel Jan H. Voss Victoria J. Vaaßen Christin Vielmuth Tobias Claff Christa E. Müller Irreversible Antagonists for the Adenosine A<sub>2B</sub> Receptor Molecules adenosine BRET assay covalent binding Gα<sub>15</sub> G protein activation G protein-coupled receptor |
| title | Irreversible Antagonists for the Adenosine A<sub>2B</sub> Receptor |
| title_full | Irreversible Antagonists for the Adenosine A<sub>2B</sub> Receptor |
| title_fullStr | Irreversible Antagonists for the Adenosine A<sub>2B</sub> Receptor |
| title_full_unstemmed | Irreversible Antagonists for the Adenosine A<sub>2B</sub> Receptor |
| title_short | Irreversible Antagonists for the Adenosine A<sub>2B</sub> Receptor |
| title_sort | irreversible antagonists for the adenosine a sub 2b sub receptor |
| topic | adenosine BRET assay covalent binding Gα<sub>15</sub> G protein activation G protein-coupled receptor |
| url | https://www.mdpi.com/1420-3049/27/12/3792 |
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