基于荧光蛋白生色团构建新型G-四链体荧光探针

G-quadruplexes (G4s), a essential nucleic acid secondary structure in organisms, is widely distributed at the end of telomeres and in the regulatory regions of gene expression, affecting the transmission of life information and important physiological processes. Nowadays, G4 fluorescent probes have been constructed and received extensive attention, which are quite helpful for deep exploration of the biological significance of G4. In this paper, a novel G4 probe was developedbased on the modification of the chromophore in green fluorescent protein, through introducing a side chain group (dimethylamine group) at the C2 position of the imidazolidinone by means of conjugated extension. Compared with the original structure, the pectral properties and the G4 binding ability of the probehave been significantly improved,with the emission wavelength red-shifted by 67 nm, and the fluorescence quantum yield of 0.67when combined with G4. Meanwhile, the probe exhibits good selectivity for the parallel G4 topology, which ispromising for identification of G4 conformation.In the application of biological imaging, the novel G4 probe target to the RNA G4 structure in the nucleolus, showing bright red fluorescence, which has great application prospect of realizing the visual detection of G4.