Photoswitchable fluorescent molecules (PSFMs) are widely applicable in the life sciences for super-resolution imaging. Owing to the large and hydrophobic molecular structures of PSFMs that may aggregate in a biological medium, the development of synthetic PSFMs with persistent reversible photoswitching is challenging. Here, we established a protein-surface-assisted photoswitching strategy that allows for persistent reversible fluorescence photoswitching of a PSFM in an aqueous solution. As a first step, we applied the photochromic chromophore furylfulgimide (FF) as a photoswitchable fluorescence quencher and developed a Förster resonance energy transfer-based PSFM, named FF-TMR. Most importantly, the protein-surface modification strategy allows FF-TMR to exhibit persistent reversible photoswitching performance in an aqueous solution. In fixed cells, the fluorescence intensity of FF-TMR bound to antitubulin antibody was repetitively modulated. The protein-surface-assisted photoswitching strategy will be a useful platform to broaden the utility of functionalized synthetic chromophores enabling persistent fluorescence switching that inherits their high resistance to light irradiation.

中文翻译：

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使用蛋白质表面修饰辅助的具有高光稳定性的光致变色猝灭剂的探针的持久荧光切换

光开关荧光分子 (PSFM) 广泛应用于生命科学中的超分辨率成像。由于 PSFM 的大型疏水分子结构可能会聚集在生物介质中，因此开发具有持久可逆光开关的合成 PSFM 具有挑战性。在这里，我们建立了一种蛋白质表面辅助的光开关策略，允许 PSFM 在水溶液中进行持久的可逆荧光光开关。作为第一步，我们将光致变色发色团呋喃基氟酰亚胺 (FF) 用作光开关荧光猝灭剂，并开发了一种基于 Förster 共振能量转移的 PSFM，命名为 FF-TMR。最重要的是，蛋白质表面修饰策略允许 FF-TMR 在水溶液中表现出持久的可逆光开关性能。在固定细胞中，与抗微管蛋白抗体结合的 FF-TMR 的荧光强度被重复调节。蛋白质表面辅助的光开关策略将是一个有用的平台，可以扩大功能化合成生色团的实用性，从而实现持久的荧光开关，继承其对光照射的高抵抗力。