Division of Biomolecular Science and Medicinal Chemistry, School of Pharmacy, University of Nottingham Biodiscovery Institute, University Park, Nottingham NG7 2RD, U.K.
Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, the Midlands, Nottingham NG7 2UH, U.K.
J Med Chem. 2022 Jun 23;65(12):8258-8288. doi: 10.1021/acs.jmedchem.2c00125. Epub 2022 Jun 3.
The histamine H receptor (HR) has recently been implicated in mediating cell proliferation and cancer progression; therefore, high-affinity HR-selective fluorescent ligands are desirable tools for further investigation of this behavior in vitro and in vivo. We previously reported a HR fluorescent ligand, bearing a peptide-linker, based on antagonist VUF13816 and sought to further explore structure-activity relationships (SARs) around the linker, orthostere, and fluorescent moieties. Here, we report a series of high-affinity HR fluorescent ligands varying in peptide linker composition, orthosteric targeting moiety, and fluorophore. Incorporation of a boron-dipyrromethene (BODIPY) 630/650-based fluorophore conferred high binding affinity to our HR fluorescent ligands, remarkably overriding the linker SAR observed in corresponding unlabeled congeners. Compound , both potent and subtype-selective, enabled HR visualization using confocal microscopy at a concentration of 10 nM. Molecular docking of with the human HR predicts that the optimized peptide linker makes interactions with key residues in the receptor.
组胺 H 受体（HR）最近被牵涉到介导细胞增殖和癌症进展中；因此，高亲和力的 HR 选择性荧光配体是进一步研究这种体外和体内行为的理想工具。我们之前报道了一种基于拮抗剂 VUF13816 的带有肽连接子的 HR 荧光配体，并试图进一步探索连接子、正位体和荧光部分周围的构效关系（SAR）。在这里，我们报告了一系列具有不同肽连接子组成、正位靶向部分和荧光团的高亲和力 HR 荧光配体。在我们的 HR 荧光配体中引入硼二吡咯甲川（BODIPY）630/650 基荧光团赋予了高结合亲和力，显著克服了在相应未标记同系物中观察到的连接子 SAR。化合物 ，具有高活性和亚型选择性，能够在 10 nM 的浓度下使用共聚焦显微镜可视化 HR。与人类 HR 的分子对接预测，优化的肽连接子与受体中的关键残基相互作用。
