Cholesterol is an essential component of most biological membranes and serves important functions in controlling membrane integrity, organization, and signaling. However, probes to follow the dynamic distribution of cholesterol in live cells are scarce and so far show only limited applicability. Herein, we addressed this problem by synthesizing and characterizing a class of versatile and clickable cholesterol-based imidazolium salts. We show that these cholesterol analogs faithfully mimic the biophysical properties of natural cholesterol in phospholipid mono- and bilayers, and that they integrate into the plasma membrane of cultured and primary human cells. The membrane-incorporated cholesterol analogs can be specifically labeled by click chemistry and visualized in live-cell imaging experiments that show a distribution and behavior comparable with that of endogenous membrane cholesterol. These results indicate that the cholesterol analogs can be used to reveal the dynamic distribution of cholesterol in live cells.

中文翻译：

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用于细胞膜实时成像的可寻址胆固醇类似物

胆固醇是大多数生物膜的重要组成部分，在控制膜的完整性，组织和信号传导中起着重要的作用。但是，缺乏追踪胆固醇在活细胞中动态分布的探针，到目前为止，其应用性有限。本文中，我们通过合成和表征一类通用且可点击的基于胆固醇的咪唑鎓盐来解决此问题。我们表明，这些胆固醇类似物忠实地模拟了磷脂单层和双层中天然胆固醇的生物物理特性，并且它们已整合到培养的和原代人细胞的质膜中。可以通过点击化学方法对掺有膜的胆固醇类似物进行特异性标记，并在活细胞成像实验中对其进行可视化，显示出与内源性膜胆固醇相当的分布和行为。这些结果表明胆固醇类似物可用于揭示胆固醇在活细胞中的动态分布。