Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany.
J Med Chem. 2020 May 28;63(10):5297-5311. doi: 10.1021/acs.jmedchem.0c00160. Epub 2020 May 18.
Comprehensively characterized fluorescent probes for the histamine H receptor (HR) and especially for the HR orthologs [e.g., human (h) and mouse (m)] are highly needed as versatile complementary tools to radioligands. In view of fluorescent probes for BRET-based binding studies and for localizing the HR in live cells, we synthesized and biologically characterized Py-5-labeled histamine derivatives. The most notable compound was UR-DEBa242 (, 1-[4-(1-Imidazol-4-yl)butyl]-4-{(1,3)-4-[4-(dimethylamino)phenyl]buta-1,3-dienyl}-2,6-dimethylpyridinium hydrotrifluoroacetate trifluoroacetate), acting as a partial agonist at the hHR [pEC (reporter gene) 8.77] and as an inverse agonist/antagonist at the h/mHRs [pIC (reporter gene) 8.76/7.08; pIC/p (β-arrestin2) 7.81/7.30]. In confocal microscopy, proved suitable for hHR localization and trafficking studies in live cells. BRET-based binding at the NLuc-hHRs/mHR [p 8.78/7.75/7.18, comparable to binding constants from radioligand binding/flow cytometry; fast association/dissociation (∼2 min)] revealed as a useful molecular tool to determine hHRs/mHR binding affinities of ligands binding to these receptors.
作为放射性配体的多功能互补工具，人们非常需要全面表征用于组胺 H 受体 (HR)、特别是用于 HR 同源受体（如人 (h) 和鼠 (m)）的荧光探针。鉴于基于 BRET 的结合研究和在活细胞中定位 HR 的荧光探针，我们合成并对 Py-5 标记的组胺衍生物进行了生物学表征。最引人注目的化合物是 UR-DEBa242（，1-[4-(1-咪唑-4-基)丁基]-4-{(1,3)-4-[4-(二甲基氨基)苯基]丁-1,3-二烯基}-2,6-二甲基吡啶翁氢三氟乙酸盐三氟乙酸盐），它作为 hHR 的部分激动剂[pEC（报告基因）8.77]和 h/mHRs 的反向激动剂/拮抗剂[pIC（报告基因）8.76/7.08；pIC/p（β-arrestin2）7.81/7.30]。在共焦显微镜中， 适合用于活细胞中 hHR 的定位和贩运研究。NLuc-hHRs/mHR 上基于 BRET 的结合[p 8.78/7.75/7.18，与放射性配体结合/流式细胞术的结合常数相当；快速缔合/解离（∼2 min）]表明 是一种有用的分子工具，可用于确定与这些受体结合的配体对 hHRs/mHR 的结合亲和力。
