Wang Baogang, Yu Shichong, Chai Xiaoyun, Li Tiejun, Wu Qiuye, Wang Ting
College of Pharmacy, Second Military Medical University, Shanghai, 200433, P. R. China.
Chemistry. 2016 Apr 11;22(16):5649-56. doi: 10.1002/chem.201505054. Epub 2016 Mar 2.
The requirement for nitric oxide (NO) of lysosomes has motivated the development of a sophisticated fluorescent probe to monitor the distribution of this important biomolecule at the subcellular level in living cells. A near-infrared (NIR) fluorescent Si-rhodamine (SiRB)-NO probe was designed based on the NO-induced ring-opening process of Si-rhodamine. The probe exhibits fast chromogenic and fluorogenic responses, and high sensitivity and selectivity toward trace amounts of NO. Significantly, the spirolactam in Si-rhodamine exhibits very good tolerance to H(+), which in turn brings extremely low background fluorescence not only in the physiological environment but also under acidic conditions. The stability of the highly fluorescent product in acidic solution provides persistent fluorescence emission for long-term imaging experiments. To achieve targeted imaging with improved spatial resolution and sensitivity, an efficient lysosome-targeting moiety was conjugated to a SiRB-NO probe, affording a tailored lysosome-targeting NIR fluorescent Lyso-SiRB-NO probe. Inheriting the key advantages of its parent SiRB-NO probe, Lyso-SiRB-NO is a functional probe that is suited for monitoring lysosomal NO with excellent lysosome compatibility. Imaging experiments demonstrated the monitoring of both exogenous and endogenous NO in real time by using the Lyso-SiRB-NO probe.
溶酶体对一氧化氮（NO）的需求促使人们开发一种精密的荧光探针，以监测这种重要生物分子在活细胞亚细胞水平的分布。基于硅罗丹明的NO诱导开环过程，设计了一种近红外（NIR）荧光硅罗丹明（SiRB）-NO探针。该探针表现出快速的显色和荧光响应，以及对痕量NO的高灵敏度和选择性。值得注意的是，硅罗丹明中的螺内酰胺对H(+)表现出非常好的耐受性，这反过来不仅在生理环境中，而且在酸性条件下都带来极低的背景荧光。高荧光产物在酸性溶液中的稳定性为长期成像实验提供了持续的荧光发射。为了实现具有更高空间分辨率和灵敏度的靶向成像，将一种高效的溶酶体靶向部分与SiRB-NO探针偶联，得到一种定制的溶酶体靶向近红外荧光Lyso-SiRB-NO探针。Lyso-SiRB-NO继承了其母体SiRB-NO探针的关键优势，是一种功能探针，适用于监测溶酶体NO，具有出色的溶酶体兼容性。成像实验证明，使用Lyso-SiRB-NO探针可以实时监测外源性和内源性NO。
