Fluorescence-labeled receptor ligands have emerged as valuable molecular tools, being indispensable for studying receptor-ligand interactions by fluorescence-based techniques such as high-content imaging, fluorescence microscopy, and fluorescence polarization. Through application of a new labeling strategy for peptides, a series of fluorescent neurotensin(8-13) derivatives was synthesized by attaching red-emitting fluorophores (indolinium- and pyridinium-type cyanine dyes) to carbamoylated arginine residues in neurotensin(8-13) analogues, yielding fluorescent probes with high NTS1R affinity (pK i values: 8.15-9.12) and potency (pEC50 values (Ca2+ mobilization): 8.23-9.43). Selected fluorescent ligands were investigated by flow cytometry and high-content imaging (saturation binding, kinetic studies, and competition binding) as well as by confocal microscopy using intact CHO-hNTS1R cells. The study demonstrates the applicability of the fluorescent probes as molecular tools to obtain, for example, information about the localization of receptors in cells and to determine binding affinities of nonlabeled ligands.

中文翻译：

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通过精氨酸残基对神经降压素（8-13）进行荧光标记，使分子工具具有高受体亲和力。

荧光标记的受体配体已经成为有价值的分子工具，对于通过基于荧光的技术（例如高含量成像，荧光显微镜和荧光偏振）研究受体-配体相互作用而言，必不可少。通过应用新的肽标记策略，通过将红色发射荧光团（吲哚鎓和吡啶鎓型花青染料）连接到神经降压素的氨基甲酰化精氨酸残基上，合成了一系列荧光神经降压素（8-13）衍生物（8-13）类似物，产生具有高NTS1R亲和力（pK i值：8.15-9.12）和效价（pEC50值（Ca2 +动员）：8.23-9.43）的荧光探针。通过流式细胞仪和高内涵成像（饱和结合，动力学研究，和竞争结合），以及使用完整的CHO-hNTS1R细胞进行共聚焦显微镜检查。该研究证明了荧光探针作为分子工具的适用性，以获取例如有关细胞中受体定位的信息以及确定未标记配体的结合亲和力的信息。