Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan.
Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan.
Philos Trans A Math Phys Eng Sci. 2017 Nov 28;375(2107). doi: 10.1098/rsta.2017.0018.
A multicolour protein labelling technique using a protein tag and fluorogenic probes is a powerful approach for spatio-temporal analyses of proteins in living cells. Since cyanine fluorophores have attractive properties for multicolour imaging of proteins, there is a huge demand to develop fluorogenic cyanine probes for specific protein labelling in living cells. Herein, we develop fluorogenic cyanine probes for labelling a protein tag by using a dinitrobenzene fluorescence quencher. The probes enhanced fluorescence intensity upon labelling reactions and emitted orange or far-red fluorescence. Intramolecular interactions between the cyanine fluorophores and the dinitrobenzene quencher led not only to fluorescence quenching of the probes in the free state but also to promotion of labelling reactions. Furthermore, the probes successfully imaged cell-surface proteins without a washing process. These findings offer valuable information on the design of fluorogenic cyanine probes and indicate that the probes are useful as novel live-cell imaging tools.This article is part of the themed issue 'Challenges for chemistry in molecular imaging'.
一种使用蛋白质标签和荧光探针的多色蛋白质标记技术，是对活细胞内蛋白质进行时空分析的有力方法。由于花青荧光团具有对蛋白质进行多色成像的诱人特性，因此人们迫切需要开发用于活细胞中特定蛋白质标记的荧光花青探针。在此，我们通过使用二硝基苯荧光猝灭剂来开发用于标记蛋白质标签的荧光花青探针。探针在标记反应后增强了荧光强度，并发出橙色或远红色荧光。花青荧光团和二硝基苯猝灭剂之间的分子内相互作用不仅导致探针在游离状态下的荧光猝灭，而且还促进了标记反应。此外，这些探针无需洗涤过程即可成功地对细胞表面蛋白进行成像。这些发现为荧光花青探针的设计提供了有价值的信息，并表明这些探针可用作新型活细胞成像工具。本文是“分子成像面临的挑战”主题特刊的一部分。
