Department of Pharmaceutical Sciences, Medicinal Chemistry Section "Pietro Pratesi", University of Milan, Via L. Mangiagalli 25, 20133 Milan, Italy.
Institute for Molecular Cell Biology, Center for Molecular Biomedicine, University Hospital Jena, Friedrich Schiller University Jena, Hans Knoell Str. 2, 07745 Jena, Germany.
Molecules. 2023 Mar 6;28(5):2407. doi: 10.3390/molecules28052407.
In the last few years, fluorescence resonance energy transfer (FRET) receptor sensors have contributed to the understanding of GPCR ligand binding and functional activation. FRET sensors based on muscarinic acetylcholine receptors (mAChRs) have been employed to study dual-steric ligands, allowing for the detection of different kinetics and distinguishing between partial, full, and super agonism. Herein, we report the synthesis of the two series of bitopic ligands, and and their pharmacological investigation at the M, M, M, and M FRET-based receptor sensors. The hybrids were prepared by merging the pharmacophoric moieties of the M/M-preferring orthosteric agonist Xanomeline and the M-selective positive allosteric modulator 77-LH-28-1 (1-[3-(4-butyl-1-piperidinyl)propyl]-3,4-dihydro-2(1H)-quinolinone) . The two pharmacophores were connected through alkylene chains of different lengths (C3, C5, C7, and C9). Analyzing the FRET responses, the tertiary amine compounds , , and evidenced a selective activation of M mAChRs, while the methyl tetrahydropyridinium salts , , and showed a degree of selectivity for M and M mAChRs. Moreover, whereas hybrids showed an almost linear response at the M subtype, hybrids evidenced a bell-shaped activation response. This different activation pattern suggests that the positive charge anchoring the compound to the orthosteric site ensues a degree of receptor activation depending on the linker length, which induces a graded conformational interference with the binding pocket closure. These bitopic derivatives represent novel pharmacological tools for a better understanding of ligand-receptor interactions at a molecular level.
在过去的几年中,荧光共振能量转移(FRET)受体传感器促进了对 G 蛋白偶联受体(GPCR)配体结合和功能激活的理解。基于毒蕈碱乙酰胆碱受体(mAChR)的 FRET 传感器已被用于研究双重立体配体,允许检测不同的动力学并区分部分激动剂、完全激动剂和超激动剂。在此,我们报告了两个系列双位配体和的合成及其在基于 FRET 的 M、M、M 和 M 受体传感器上的药理学研究。这些杂种是通过合并 M/M 偏好的正构激动剂 Xanomeline 和 M 选择性正变构调节剂 77-LH-28-1(1-[3-(4-丁基-1-哌啶基)丙基]-3,4-二氢-2(1H)-喹啉酮)的药效团而制备的。两个药效团通过不同长度的亚乙基链(C3、C5、C7 和 C9)连接。通过分析 FRET 反应,叔胺化合物、和表现出对 M mAChR 的选择性激活,而甲基四氢吡啶盐、、和则表现出对 M 和 M mAChR 的一定程度的选择性。此外,尽管杂化物在 M 亚型上表现出几乎线性的响应,但杂化物则表现出钟形激活响应。这种不同的激活模式表明,将化合物锚定在正位点的正电荷会根据接头长度引发一定程度的受体激活,从而导致与结合口袋闭合的构象干扰呈分级变化。这些双位衍生物代表了更好地理解配体-受体相互作用的新型药理学工具。