Verna and Marrs McLean Department of Biochemistry and Molecular Biology , Baylor College of Medicine, Houston , Texas 77030 , United States.
Published: September 2019
AI Article Synopsis
Article Abstract
Photoactivatable fluorophores afford powerful molecular tools to improve the spatial and temporal resolution of subcellular structures and dynamics. By performing a single sulfur-for-oxygen atom replacement within common fluorophores, we have developed a facile and general strategy to obtain photoactivatable fluorogenic dyes across a broad spectral range. Thiocarbonyl substitution within fluorophores results in significant loss of fluorescence via a photoinduced electron transfer-quenching mechanism as suggested by theoretical calculations. Significantly, upon exposure to air and visible light residing in their absorption regime (365-630 nm), thio-caged fluorophores can be efficiently desulfurized to their oxo derivatives, thus restoring strong emission of the fluorophores. The effective photoactivation makes thio-caged fluorophores promising candidates for super-resolution imaging, which was realized by photoactivated localization microscopy (PALM) with low-power activation light under physiological conditions in the absence of cytotoxic additives (e.g., thiols, oxygen scavengers), a feature superior to traditional PALM probes. The versatility of this thio-caging strategy was further demonstrated by multicolor super-resolution imaging of lipid droplets and proteins of interest.
State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
Thio-caged fluorophores can be effectively desulfurized into their oxygenated derivatives through visible light, thereby restoring the strong emission of fluorophores, and are applied in the field of live cell super-resolution imaging. Herein, we theoretically investigated the reasons for the low fluorescence quantum yields of a series of thio-caged fluorophores and the underlying reasons for the differences in fluorescence quantum yields of their oxygenated derivatives. The calculation results show that the S atom on the thiocarbonyl group is more likely to excite n electrons to form the nπ* state, which reduces the energy of the nπ* state and leads to fluorescence quenching.
Photoactivatable fluorophores afford powerful molecular tools to improve the spatial and temporal resolution of subcellular structures and dynamics. By performing a single sulfur-for-oxygen atom replacement within common fluorophores, we have developed a facile and general strategy to obtain photoactivatable fluorogenic dyes across a broad spectral range. Thiocarbonyl substitution within fluorophores results in significant loss of fluorescence via a photoinduced electron transfer-quenching mechanism as suggested by theoretical calculations.
