The long‐term stability of affinity‐based protein labeling probes is crucial to obtain reproducible protein labeling results. However, highly stable probes generally suffer from low protein labeling efficiency and pose significant challenges when labeling low abundance native proteins in living cells. In this paper, we report that protein labeling probes based on an ortho‐difluorophenyl ester reactive module exhibit long‐term stability in DMSO stock solution and aqueous buffer, yet they can undergo rapid and selective labeling of native proteins. This novel electrophile can be customized with a wide range of different protein ligands and is particularly well‐suited for the labeling and imaging of transmembrane proteins. With this probe design, the identity and relative levels of basal and hypoxia‐induced transmembrane carbonic anhydrases were revealed by live cell imaging and in‐gel fluorescence analysis. We believe that the extension of this difluorophenyl ester reactive module would allow for the specific labeling of various endogenous membrane proteins, facilitating in‐depth studies of their distribution and functions in biological processes.

中文翻译：

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基于二氟苯基酯亲和力的探针对活细胞中内源性跨膜蛋白进行快速和选择性标记。

基于亲和力的蛋白质标记探针的长期稳定性对于获得可再现的蛋白质标记结果至关重要。然而，高度稳定的探针通常遭受低的蛋白质标记效率，并且在标记活细胞中的低丰度天然蛋白质时提出了重大挑战。在本文中，我们报道了基于邻二氟苯基酯反应性模块的蛋白质标记探针在DMSO储备溶液和水性缓冲液中具有长期稳定性，但是它们可以对天然蛋白质进行快速且选择性的标记。该新型亲电试剂可定制各种不同的蛋白质配体，特别适合跨膜蛋白的标记和成像。通过这种探头设计，通过活细胞成像和凝胶内荧光分析揭示了基础和低氧诱导的跨膜碳酸酐酶的身份和相对水平。我们相信，这种二氟苯基酯反应性模块的扩展将允许对各种内源性膜蛋白进行特异性标记，从而有助于对其在生物过程中的分布和功能的深入研究。