Department of Chemistry and Pharmacy, Medicinal Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Nikolaus-Fiebiger-Str. 10, 91058, Erlangen, Germany.
Sci Rep. 2020 Dec 14;10(1):21842. doi: 10.1038/s41598-020-78827-9.
Fluorescent ligands are versatile tools for the study of G protein-coupled receptors. Depending on the fluorophore, they can be used for a range of different applications, including fluorescence microscopy and bioluminescence or fluorescence resonance energy transfer (BRET or FRET) assays. Starting from phenylpiperazines and indanylamines, privileged scaffolds for dopamine D-like receptors, we developed dansyl-labeled fluorescent ligands that are well accommodated in the binding pockets of D and D receptors. These receptors are the target proteins for the therapy for several neurologic and psychiatric disorders, including Parkinson's disease and schizophrenia. The dansyl-labeled ligands exhibit binding affinities up to 0.44 nM and 0.29 nM at DR and DR, respectively. When the dansyl label was exchanged for sterically more demanding xanthene or cyanine dyes, fluorescent ligands 10a-c retained excellent binding properties and, as expected from their indanylamine pharmacophore, acted as agonists at DR. While the Cy3B-labeled ligand 10b was used to visualize DR and DR on the surface of living cells by total internal reflection microscopy, ligand 10a comprising a rhodamine label showed excellent properties in a NanoBRET binding assay at DR.
荧光配体是研究 G 蛋白偶联受体的多功能工具。根据荧光团的不同，它们可用于一系列不同的应用，包括荧光显微镜和生物发光或荧光共振能量转移（BRET 或 FRET）测定。从苯并哌嗪和吲唑胺开始，这是多巴胺 D 样受体的优势骨架，我们开发了丹磺酰基标记的荧光配体，这些配体很好地适应了 D 和 D 受体的结合口袋。这些受体是治疗多种神经和精神疾病的靶蛋白，包括帕金森病和精神分裂症。丹磺酰基标记的配体在 DR 和 DR 上的结合亲和力分别高达 0.44 nM 和 0.29 nM。当丹磺酰基标记被空间要求更高的呫吨或花青染料取代时，荧光配体 10a-c 保留了优异的结合特性，并且根据其吲唑胺药效团，在 DR 上表现为激动剂。当 Cy3B 标记的配体 10b 用于通过全内反射显微镜在活细胞表面可视化 DR 和 DR 时，包含罗丹明标记的配体 10a 在 DR 的 NanoBRET 结合测定中表现出优异的性能。
