Yang Sheng, Qi Yue, Liu Changhui, Wang Yijun, Zhao Yirong, Wang Lili, Li Jishan, Tan Weihong, Yang Ronghua
State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, and Collaborative Innovation Center for Chemistry and Molecular Medicine, Hunan University , Changsha, 410082, China.
Anal Chem. 2014 Aug 5;86(15):7508-15. doi: 10.1021/ac501263d. Epub 2014 Jul 14.
Molecular tools capable of providing information on a target analyte in an organelle of interest are especially appreciated. Traditionally, organelle-targetable probes are designed by incorporating an organelle-specific guiding unit to target the probe molecules into the organelle. The imperfect targeting function of the guiding unit and nonspecific distribution of the analyte in cytosol and each organelle would lead to low spatiotemporal resolution and limited sensitivity. To solve this problem, we report herein a new approach for detection of a target analyte in a specific organelle by engineering a target and location dual-controlled molecular switch. For this proof-of-concept study, fluorescent detection of H2S in lysosomes was performed with a simultaneous H2S and proton-activatable probe based on the acidic environment of lysosomes. The new synthesized fluorescent sensor, "SulpHensor", which contains a spirolactam moiety to bind hydrogen protons and an azide group to react with H2S, displays highly sensitive and selective fluorescence response to H2S under lysosomal pH environment but is out of operation in neutral cytosol and other organelles. Fluorescence imaging shows that SulpHensor is membrane-permeable and suitable for visualization of both the exogenous and endogenous H2S in lysosomes of living cells. The good performance of our proposed approach for H2S sensing demonstrates that this strategy might open up new opportunities for the development of efficient subcellular molecular tools for bioanalytical and biomedical applications.
能够提供有关感兴趣细胞器中目标分析物信息的分子工具尤其受到青睐。传统上，可靶向细胞器的探针是通过引入细胞器特异性引导单元来将探针分子靶向到细胞器中进行设计的。引导单元的靶向功能不完善以及分析物在细胞质和各个细胞器中的非特异性分布会导致时空分辨率低和灵敏度有限。为了解决这个问题，我们在此报告一种通过设计目标和位置双控分子开关来检测特定细胞器中目标分析物的新方法。对于这项概念验证研究，基于溶酶体的酸性环境，使用同时对H2S和质子可激活的探针进行了溶酶体中H2S的荧光检测。新合成的荧光传感器“SulpHensor”，它含有一个用于结合氢离子的螺内酰胺部分和一个用于与H2S反应的叠氮基团，在溶酶体pH环境下对H2S表现出高度灵敏和选择性的荧光响应，但在中性细胞质和其他细胞器中不起作用。荧光成像表明，SulpHensor具有膜通透性，适用于可视化活细胞溶酶体中外源和内源H2S。我们提出的H2S传感方法的良好性能表明，这种策略可能为开发用于生物分析和生物医学应用的高效亚细胞分子工具开辟新的机会。
