Tian Minggang, Guo Fuqiang, Sun Yuming, Zhang Weijia, Miao Fang, Liu Yong, Song Guofen, Ho Cheuk-Lam, Yu Xiaoqiang, Sun Jing Zhi, Wong Wai-Yeung
Centre of Bio and Micro/Nano Functional Materials, State Key Lab of Crystal Materials, Shandong University, Jinan 250100, P. R. China.
Org Biomol Chem. 2014 Aug 28;12(32):6128-33. doi: 10.1039/c4ob00382a. Epub 2014 Jul 3.
Cysteine (Cys) plays important roles in many physiological processes of eukaryotic cells and its detection in cells is of fundamental significance. However, glutathione (GSH), homocysteine, N-acetyl-L-cysteine and other thiols greatly hamper the detection of Cys. In particular, GSH strongly interferes with the detection of cellular Cys (30–200 μM) due to its high intracellular concentration (1–10 mM). In this work, an off–on fluorescent probe (HOTA) for the detection of Cys is presented. This probe possesses both excellent sensitivity and satisfactory selectivity for cellular Cys detection: with the addition of 200 μM Cys, the fluorescence intensity of the probe (10 μM) enhanced 117-fold and the detection limit was calculated to be 13.47 μM, which is lower than the cellular Cys concentration; the probe also selectively detected 30–200 μM cysteine over 1–10 mM glutathione. Consequently, cell imaging experiments were performed with probe HOTA. Furthermore, the results of the thiol-blocking and GSH synthesis inhibiting experiments confirmed that the intracellular emission mainly originates from the interaction between Cys and HOTA.
半胱氨酸（Cys）在真核细胞的许多生理过程中发挥着重要作用，在细胞中检测半胱氨酸具有重要的基础意义。然而，谷胱甘肽（GSH）、同型半胱氨酸、N - 乙酰 - L - 半胱氨酸和其他硫醇会极大地干扰半胱氨酸的检测。特别是，由于细胞内谷胱甘肽浓度较高（1 - 10 mM），它会强烈干扰细胞内半胱氨酸（30 - 200 μM）的检测。在这项工作中，提出了一种用于检测半胱氨酸的开 - 关型荧光探针（HOTA）。该探针对于细胞内半胱氨酸的检测具有出色的灵敏度和令人满意的选择性：加入200 μM半胱氨酸后，探针（10 μM）的荧光强度增强了117倍，计算得出的检测限为13.47 μM，低于细胞内半胱氨酸的浓度；该探针还能在1 - 10 mM谷胱甘肽存在的情况下选择性地检测30 - 200 μM的半胱氨酸。因此，使用探针HOTA进行了细胞成像实验。此外，硫醇阻断和谷胱甘肽合成抑制实验的结果证实，细胞内的荧光发射主要源于半胱氨酸与HOTA之间的相互作用。
