Li Zeng

Publications of Li Zeng

• Visualizing ascorbate-triggered release of labile copper within living cells using a ratiometric fluorescent sensor.

  Authors: Dylan W Domaille, Li Zeng, Christopher J Chang

  Journal of the American Chemical Society. 02/2010; 132(4):1194-5.

  We present the synthesis, properties, and biological applications of Ratio-Coppersensor-1 (RCS1), a new water-soluble fluorescent sensor for ratiometric imaging of copper in living cells. RCS1We present the synthesis, properties, and biological applications of Ratio-Coppersensor-1 (RCS1), a new water-soluble fluorescent sensor for ratiometric imaging of copper in living cells. RCS1 combines an asymmetric BODIPY reporter and thioether-based ligand receptor to provide high selectivity and sensitivity for Cu(+) over other biologically relevant metal ions, including Cu(2+) and Zn(2+), a ca. 20-fold fluorescence ratio change upon Cu(+) binding, and visible excitation and emission profiles compatible with standard fluorescence microscopy filter sets. Live-cell confocal microscopy experiments show that RCS1 is membrane-permeable and can sense changes in the levels of labile Cu(+) pools within living cells by ratiometric imaging, including expansion of endogenous stores of exchangeable intracellular Cu(+) triggered by ascorbate stimulation in kidney and brain cells.

• Preparation and use of Coppersensor-1, a synthetic fluorophore for live-cell copper imaging.

  Authors: Evan W Miller, Li Zeng, Dylan W Domaille, Christopher J Chang

  Nature protocols. 02/2006; 1(2):824-7.

  Coppersensor-1 (CS1) is a small-molecule, membrane-permeable fluorescent dye for imaging labile copper pools in biological samples, including live cells. This probe, comprising a boron dipyrrometheneCoppersensor-1 (CS1) is a small-molecule, membrane-permeable fluorescent dye for imaging labile copper pools in biological samples, including live cells. This probe, comprising a boron dipyrromethene (BODIPY) chromophore coupled to a thioether-rich receptor, has a picomolar affinity for Cu+ with high selectivity over competing cellular metal ions. CS1 fluorescence increases up to 10-fold on binding to Cu+. In this protocol we describe the synthesis of CS1 and how to use this chemical tool to investigate intracellular levels of labile copper in cultured cells. The preparation of CS1 is anticipated to take 4-5 d, and imaging assays can be performed in 1-2 d with cultured cells.

• A selective turn-on fluorescent sensor for imaging copper in living cells.

  Authors: Li Zeng, Evan W Miller, Arnd Pralle, Ehud Y Isacoff, Christopher J Chang

  Journal of the American Chemical Society. 02/2006; 128(1):10-1.

  We present the synthesis, properties, and biological applications of Coppersensor-1 (CS1), a new water-soluble, turn-on fluorescent sensor for intracellular imaging of copper in living biologicalWe present the synthesis, properties, and biological applications of Coppersensor-1 (CS1), a new water-soluble, turn-on fluorescent sensor for intracellular imaging of copper in living biological samples. CS1 utilizes a BODIPY reporter and thioether-rich receptor to provide high selectivity and sensitivity for Cu+ over other biologically relevant metal ions, including Cu2+, in aqueous solution. This BODIPY-based probe is the first Cu+-responsive sensor with visible excitation and emission profiles and gives a 10-fold turn-on response for detecting this ion. Confocal microscopy experiments further establish that CS1 is membrane-permeable and can successfully monitor intracellular Cu+ levels within living cells.