Nakamura Akinobu, Tsukiji Shinya
Department of Materials Science and Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan.
Frontier Research Institute for Materials Science (FRIMS), Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan; Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan; Department of Nanopharmaceutical Sciences, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan.
Bioorg Med Chem Lett. 2017 Jul 15;27(14):3127-3130. doi: 10.1016/j.bmcl.2017.05.036. Epub 2017 May 12.
Small-molecule fluorescent sensors that allow specific measurement of nuclear pH in living cells will be valuable for biological research. Here we report that Hoechst-tagged fluorescein (hoeFL), which we previously developed as a green fluorescent DNA-staining probe, can be used for this purpose. Upon excitation at 405nm, the hoeFL-DNA complex displayed two fluorescence bands around 460nm and 520nm corresponding to the Hoechst and fluorescein fluorescence, respectively. When pH was changed from 8.3 to 5.5, the fluorescence intensity ratio (F/F) significantly decreased, which allowed reliable pH measurement. Moreover, because hoeFL binds specifically to the genomic DNA in cells, it was applicable to visualize the intranuclear pH of nigericin-treated and intact living human cells by ratiometric fluorescence imaging.
能够对活细胞中的核pH值进行特异性测量的小分子荧光传感器对生物学研究具有重要价值。在此我们报告，我们之前开发的作为绿色荧光DNA染色探针的Hoechst标记荧光素（hoeFL）可用于此目的。在405nm激发下，hoeFL-DNA复合物在460nm和520nm左右分别显示出对应于Hoechst和荧光素荧光的两个荧光带。当pH值从8.3变为5.5时，荧光强度比（F/F）显著降低，这使得可靠的pH测量成为可能。此外，由于hoeFL与细胞中的基因组DNA特异性结合，它可通过比率荧光成像用于可视化尼日利亚菌素处理的和完整的活人类细胞的核内pH值。
