Chen Ruirui, Ye Haishun, Fang Tian, Liu Shanshan, Yi Long, Cheng Longhuai
State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, National Pesticide Engineering Research Center (Tianjin), College of Chemistry, Nankai University, Tianjin, 300071, China.
State Key Laboratory of Organic-Inorganic Composites and Beijing Key Lab of Bioprocess, Beijing University of Chemical Technology (BUCT), 15 Beisanhuan East Road, Chaoyang District, Beijing 100029, P. R. China.
Org Biomol Chem. 2022 May 26;20(20):4128-4134. doi: 10.1039/d2ob00442a.
The thiolysis of NBD piperazinyl amine (NBD-PZ) is highly selective for HS over GSH and has been widely used for the development of many HS fluorescent probes. Whether the NBD amine in HS-specific probes could be a fluorescent quencher should be further clarified, because NBD amines have been used as environment-sensitive fluorophores for many years. Here, we compared the properties of NBD-based secondary and tertiary amines under the same conditions. For example, the emission of NBD-N(Et)2 is much smaller in water and less responsive to changes in polarity than that of NBD-NHEt. The emission of NBD-PZ-TPP is also smaller than that of NBD-NH-TPP both in aqueous buffer and in live cells. In addition, confocal bioimaging signals of NBD-PZ-TPP with excitation at 405 nm and 454 nm are much weaker than that at 488 nm. Based on these results as well as the previous work on NBD-based probes, we discuss and summarize the design strategies and sensing mechanisms for different NBD-based HS probes. Moreover, NBD-PZ-TPP may be a useful tool for reaction with and imaging of mitochondrial HS in live cells. This work should be useful for clarification of the roles of NBD in HS-specific fluorescent probes as well as for facilitating the development of future NBD-based probes.
NBD哌嗪基胺（NBD - PZ）的硫解反应对HS的选择性远高于GSH，已被广泛用于开发多种HS荧光探针。由于NBD胺多年来一直被用作对环境敏感的荧光团，因此HS特异性探针中的NBD胺是否可能是荧光猝灭剂有待进一步阐明。在此，我们在相同条件下比较了基于NBD的仲胺和叔胺的性质。例如，在水中，NBD - N(Et)2的发射比NBD - NHEt小得多，并且对极性变化的响应也较小。在水性缓冲液和活细胞中，NBD - PZ - TPP的发射也比NBD - NH - TPP小。此外，在405 nm和454 nm激发下，NBD - PZ - TPP的共聚焦生物成像信号比在488 nm激发下弱得多。基于这些结果以及之前关于基于NBD的探针的研究工作，我们讨论并总结了不同基于NBD的HS探针的设计策略和传感机制。此外，NBD - PZ - TPP可能是用于活细胞中线粒体HS反应和成像的有用工具。这项工作对于阐明NBD在HS特异性荧光探针中的作用以及促进未来基于NBD的探针的开发应该是有用的。
