- Single-Molecule Imaging of Active Mitochondrial Nitroreductases Using a Photo-Crosslinking Fluorescent Sensor
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Many biomacromolecules are known to cluster in microdomains with specific subcellular localization. In the case of enzymes, this clustering greatly defines their biological functions. Nitroreductases are enzymes capable of reducing nitro groups to amines,
- Thiel, Zacharias,Rivera-Fuentes, Pablo
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- Tuning the Photophysical Properties of Spirolactam Rhodamine Photoswitches
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Spirolactam rhodamines are fluorescent photoswitches that are useful for single molecule localization microscopy, volumetric 3D digital light photoactivatable dye displays, and other applications. Measurement of the photophysical properties, particularly photoswitching kinetics and quantum yields, is challenging and a comprehensive understanding of how molecular structure affects these parameters remains incomplete. In this study, we have synthesized a series of N-aryl spirolactam rhodamine photoswitches with fluorescent emissions at 585 nm and 518 nm. Extinction coefficients and fluorescence quantum yields of the fluorescent form of the photoswitch have been measured using excess trifluoroacetic acid to drive the equilibrium to the open form. A method to determine photoswitching kinetics and quantum yields was developed by monitoring the kinetics to reach equilibrium between the on-state and off-state and fitting this data to a rate equation for a reaction in equilibrium. Trends based on the electronic and steric properties of the aryl substituents were evaluated. Using this information, a proof-of-principle demonstration of 3D voxel formation was accomplished using a green (518 nm) emitting photoswitch, setting the foundation for a multi-colour volumetric 3D display.
- Li, Bo,Haris, Uroob,Aljowni, Maha,Nakatsuka, Andrew,Patel, Shreya K.,Lippert, Alexander R.
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- A mitochondria-targeted red-emitting probe for imaging hydrogen sulfide in living cells and zebrafish
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Hydrogen sulfide (H2S) is an important endogenous signaling molecule with multiple biological functions. Based on the thiolysis of NBD (7-nitro-1,2,3-benzoxadiazole) amine, herein we rationally design and synthesize a new fluorescent probe 1 for the detection of mitochondrial H2S in living cells. Probe 1 displays bright red-emitting fluorescence after H2S activation (φ, 0.77). 1 shows higher selectivity and sensitivity for H2S than the red-emitting probe Rho-NBD (ChemBioChem, 2016, 17, 962). Moreover, 1 is water-soluble, cell-membrane-permeable, of low cytotoxicity and mitochondria-targeting, and can be employed for monitoring mitochondrial H2S in living cells.
- Ismail, Ismail,Wang, Dan,Wang, Dawei,Niu, Cuili,Huang, Haojie,Yi, Long,Xi, Zhen
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- Super-resolution imaging of lysosomes with a nitroso-caged rhodamine
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Caged-fluorophores are potentially suitable for photo-activated localization microscopy (PALM) for super-resolution imaging. N-Nitroso is a simple and robust photo-cage with biocompatible nitric oxide as the only byproduct upon photolysis. We herein reported a novel PALM probe (NOR535) for super-resolution imaging of lysosomes with high localization precision.
- He, Haihong,Ye, Zhiwei,Zheng, Ying,Xu, Xiu,Guo, Chunlei,Xiao, Yi,Yang, Wei,Qian, Xuhong,Yang, Youjun
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- Coal-Tar Dye-based Coordination Cages and Helicates
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A strategy to implement four members of the classic coal-tar dye family, Michler's ketone, methylene blue, rhodamine B, and crystal violet, into [Pd2L4] self-assemblies is introduced. Chromophores were incorporated into bis-monodentate ligands using piperazine linkers that allow to retain the auxochromic dialkyl amine functionalities required for intense colors deep in the visible spectrum. Upon palladium coordination, ligands with pyridine donors form lantern-shaped dinuclear cages while quinoline donors lead to strongly twisted [Pd2L4] helicates in solution. In one case, single crystal X-ray diffraction revealed rearrangement to a [Pd3L6] ring structure in the solid state. For nine examined derivatives, showing colors from yellow to deep violet, CD spectroscopy discloses different degrees of chiral induction by an enantiomerically pure guest. Ion mobility mass spectrometry allows to distinguish two binding modes. Self-assemblies based on this new ligand class promise application in chiroptical recognition, photo-redox catalysis and optical materials.
- Regeni, Irene,Chen, Bin,Frank, Marina,Baksi, Ananya,Holstein, Julian J.,Clever, Guido H.
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supporting information
p. 5673 - 5678
(2021/02/03)
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- A chemoselective cleavable fluorescence turn-ON linker for proteomic studies
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We have developed a trifunctional cleavable fluorescence turn-ON linker for chemoproteomic applications. This novel linker, which became highly fluorescent only upon cleavage of the azo bond, was successfully used for in situ proteome profiling/target identification and studies on newly synthesised proteomes.
- Liew, Si Si,Du, Shubo,Ge, Jingyan,Pan, Sijun,Jang, Se-Young,Lee, Jun-Seok,Yao, Shao Q.
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supporting information
p. 13332 - 13335
(2017/12/26)
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- Synthesis of rhodamines from fluoresceins using pd-catalyzed c-n cross-coupling
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A unified, convenient, and efficient strategy for the preparation of rhodamines and N,N′-diacylated rhodamines has been developed. Fluorescein ditriflates were found to undergo palladium-catalyzed C-N cross-coupling with amines, amides, carbamates, and other nitrogen nucleophiles to provide direct access to known and novel rhodamine derivatives, including fluorescent dyes, quenchers, and latent fluorophores.
- Grimm, Jonathan B.,Lavis, Luke D.
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supporting information; experimental part
p. 6354 - 6357
(2012/02/01)
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