Development of a light-up fluorescent probe for HRAS G-quadruplex DNA

作者:Wang, Ming-Qi*; Wang, Zi-Yu; Yang, Yi-Fan; Ren, Gui-Ying; Liu, Xiao-Ning; Li, Shuo*; Wei, Jian-Wei; Zhang, Lan
来源:Tetrahedron Letters, 2017, 58(33): 3296-3300.
DOI:10.1016/j.tetlet.2017.07.032

摘要

The development of small-molecule G-quadruplex DNA probes has attracted significant attention in recent years. However, G-quadruplexes can display a wide variety of topologies, which process different structures and functions. Therefore, selective discrimination one G-quadruplex structure over another is promising. Herein, we reported the design, synthesis and biological evaluation of a long-chain fatty amine functionalized triphenylamine-quinolinium conjugate 1b. Significant enhancement of the fluorescence intensity (over 180 fold) was observed when 1b bound with HRAS G-quadruplex DNA, while much weaker enhancements were presented in the presence of other G-quadruplexes (45-90-fold) and single/double-stranded DNAs (less than 20-fold), indicating 1b had an excellent selectivity to HRAS. The details of the interactions were investigated by UV-Vis, FID and CD analysis. The results show 1b could interact and stabilize HRAS structure mainly by pi-pi stacking binding mode. The introduced amine chain of the structure core was found to be better in the terms of inducing selectivity toward G-quadruplex structure. In addition, the application of 1b as a fluorescent agent for living cell imaging was also demonstrated.