NBD-Based Environment-Sensitive Fluorescent Probes for the Human Ether-a-Go-Go–Related Gene Potassium Channel

Figures

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  SCHEME 1. (A) Design principle of fluorescent probes. (B) Chemical structures of small-molecule fluorescent probes M1–M3.

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  FIGURE 1. Synthetic routes of fluorescent probes M1, M2, and M3.

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  FIGURE 2. (A) Fluorescent excitation and (B) emission spectra of probe M1 in different solvents.

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  FIGURE 3. (A) Fluorescent excitation and (B) emission spectra of probe M2 in different solvents.

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  FIGURE 4. (A) Fluorescent excitation and (B) emission spectra of probe M3 in different solvents.

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  FIGURE 5. Fluorescence microscopy imaging of hERG-transfected HEK293 cells incubated with 1.0 μM probe M1 (A1: bright field; A2: GFP channel), 5.0 μM probe M2 (B1: bright field; B2: GFP channel), and 5.0 μM probe M3 (C1: bright field; C2: GFP channel). The imaging of inhibition of the hERG channels was accomplished by incubating astemizole (10, 50, and 50 μM) with probes M1 (1.0 μM; A3: bright field; A4: GFP channel), M2 (5.0 μM; B3: bright field; B4: GFP channel), and M3 (5.0 μM; C3: bright field; C4: GFP channel). All cells were incubated with each probe at 37°C for 10 min and washed immediately. The background was adjusted by ImageJ software. Imaging was performed using a Zeiss Axio Observer A1 microscope with a ×63 objective lens. Scale bar = 20 μm.