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. 2009;48(48):9097-101.
doi: 10.1002/anie.200904504.

Photochromic blockers of voltage-gated potassium channels

Matthew R Banghart  1 , Alexandre Mourot, Doris L Fortin, Jennifer Z Yao, Richard H Kramer, Dirk Trauner
Affiliations

Photochromic blockers of voltage-gated potassium channels

Matthew R Banghart et al. Angew Chem Int Ed Engl. 2009.
No abstract available

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Figures

Figure 1
Figure 1
Photocontrol of K+ channels. a) Structures and photoisomerization of photoswitchable K+ channel blockers. b) Cartoon depicting a PCL for the internal TEA-binding site. The linear trans isomer is a better blocker than the bent cis isomer. c) Cartoon depicting a PTL for the external TEA-binding site. The extended trans isomer presents the blocking particle to the pore while the shorter cis isomer is unable to reach. PCL: photochromic ligand, PTL: photoswitchable tethered ligand, TEA: tetraethylammonium.
Figure 2
Figure 2
AAQ is an open-channel blocker of the Sh-IR internal TEA-binding site. a & b) Whole-cell current responses to 200 ms depolarizing voltage steps from −70 to +40 mV in the presence of 380 nm (gray) or 500 nm (black) light. a) Open-channel block is apparent in AAQ-treated Sh-IR channels (Scale bar: 6 nA, 25 ms.) b) Open-channel block is absent in MAQ-treated SPARK channels (Scale bar: 0.5 nA, 25 ms.) c) Steady-state I/V curves under 380 nm (gray), 420 nm (black dashes) and 500 nm (black) illumination. I/V curves from each of 4 cells were normalized to the current measured at 380 nm and +60 mV. d) Dependence of AAQ block on [K+]o. Whole-cell current responses of a cell to depolarizing voltage steps from –70 to +40 mV in the presence of 380 nm (gray) or 500 nm (black) light at the indicated [K+]o. Similar results were obtained in 2 other cells (Scale bar: 5 nA, 50 ms.)
Figure 3
Figure 3
AAQ is a PCL for the internal-TEA binding site of Sh-IR. (a) Iss recorded from inside-out patches as AAQ was applied at the indicated concentrations (μM). (b) Dose-response relationships for AAQ applied to inside-out patches under 500 nm (black) and 380 nm (gray) illumination.
Figure 4
Figure 4
PCLs persistently photosensitize Sh-IR. Iss over time recorded from a cell treated with a) 400 μM AAQ, b) 20 μM BzAQ (7) and c) 40 μM PrAQ (10) under 380 nm (gray bars) and 500 nm (black bars) illumination. d) Dose-response relationships for BzAQ (7) applied to inside-out patches under 500 nm (black) and 380 nm (gray) illumination.
Figure 5
Figure 5
BzAQ photoregulates endogenous K+ channels in dissociated hippocampal neurons to modulate neural activity. a) Steady-state I/V curves under 380 nm (gray) and 500 nm (black) illumination recorded from neurons treated with 20 μM BzAQ. Recordings from 4 individual cells were normalized to the current measured at 380 nm and +70 mV. b) Current clamp recording from a neuron showing the induction of action potential firing in response to 500 nm light (black). Scale bar: 10 mV, 10 s. Similar results were obtained in at least 3 additional cells.
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References

    1. Kaufman H, Vratsanos SM, Erlanger BF. Science. 1968;162:1487–1489. - PubMed
    1. Wainberg MA, Erlanger BF. Biochemistry. 1971;10:3816–3819. - PubMed
    1. Harvey AJ, Abell AD. Tetrahedron. 2000;56:9763–9771.
    1. Deal WJ, Jr, Erlanger BF, Nachmansohn D. Proc Natl Acad Sci USA. 1969;64:1230–1234. - PMC - PubMed
    1. Bartels E, Wassermann NH, Erlanger BF. Proc Natl Acad Sci USA. 1971;68:1820–1823. - PMC - PubMed

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