A dual emission fluorescent probe enables simultaneous detection of glutathione and cysteine/homocysteine.
A dual emission fluorescent probe enables simultaneous detection of glutathione and cysteine/homocysteine.
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DOI：
10.1039/c4sc00308j
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发表时间：
2014-06-01
期刊：
影响因子：
8.4
通讯作者：
Strongin RM
中科院分区：
文献类型：
--
作者：
Yang XF;Huang Q;Zhong Y;Li Z;Li H;Lowry M;Escobedo JO;Strongin RM
许多研究表明，谷胱甘肽（GSH）和半胱氨酸（Cys）/同型半胱氨酸（Hcy）水平在生物系统中是相互关联的。为了揭示GSH和Cys/Hcy参与各种疾病状态的复杂生物医学机制，非常需要响应GSH和Cys/Hcy显示不同信号的探针。在这项工作中，我们报告了一个罗丹酚硫酯（1），响应GSH和半胱氨酸/同型半胱氨酸在中性介质中具有不同的荧光发射。探针1与Cys/Hcy反应，通过串联天然化学连接（NCL）反应形成相应的解缀合螺内酰胺。这种分子内螺环化导致对羟基染料的“醌-苯酚”转导，并且在光激发时发生酚羟基质子和苯并噻唑单元中的芳族氮之间的激发态分子内质子转移（ESIPT）过程，从而提供2-（2 '-羟基苯基）苯并噻唑（HBT）发射（454 nm）。在三肽GSH的情况下，仅发生转硫酯化，除去由缺电子4-硝基苯部分引起的分子内光诱导电子转移（PET）过程，从而在rhodol发射带（587 nm）处产生大的荧光增强。GSH和Cys/Hcy的同时检测归因于衍生自1的相应硫酯加合物的分子内S，N-酰基位移速率显着不同。探针1的实用性已在包括血清和细胞的各种生物系统中得到证实。
Many studies have shown that glutathione (GSH) and cysteine (Cys) / homocysteine (Hcy) levels are interrelated in biological systems. To unravel the complicated biomedical mechanisms by which GSH and Cys/Hcy are involved in various disease states, probes that display distinct signals in response to GSH and Cys/Hcy are highly desirable. In this work, we report a rhodol thioester (1) that responds to GSH and Cys/Hcy with distinct fluorescence emissions in neutral media. Probe 1 reacts with Cys/Hcy to form the corresponding deconjugated spirolactam via a tandem native chemical ligation (NCL) reaction. This intramolecular spirocyclization leads to the “quinone – phenol” transduction of rhodol dyes, and an excited-state intramolecular proton transfer (ESIPT) process between the phenolic hydroxyl proton and the aromatic nitrogen in the benzothiazole unit occurs upon photoexcitation, thus affording 2-(2’-hydroxyphenyl) benzothiazole (HBT) emission (454 nm). In the case of the tripeptide GSH, only transthioesterification takes place removing the intramolecular photo-induced electron transfer (PET) process caused by the electron deficient 4-nitrobenzene moiety giving rise to a large fluorescence enhancement at the rhodol emission band (587 nm). The simultaneous detection of GSH and Cys/Hcy is attributed to the significantly different rates of intramolecular S,N-acyl shift of their corresponding thioester adducts derived from 1. The utility of probe 1 has been demonstrated in various biological systems including serum and cells.