1. Flipping the Switch: Reverse-Demand Voltage-Sensitive Fluorophores
- Author
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McCann, Jack T, Benlian, Brittany R, Yaeger-Weiss, Susanna K, Knudson, Isaac J, He, Minyi, and Miller, Evan W
- Subjects
Macromolecular and Materials Chemistry ,Chemical Sciences ,Electron Transport ,Fluorescent Dyes ,Ionophores ,Membrane Potentials ,Microscopy ,Fluorescence ,General Chemistry ,Chemical sciences ,Engineering - Abstract
Fluorescence microscopy with fluorescent reporters that respond to environmental cues is a powerful method for interrogating biochemistry and biophysics in living systems. Photoinduced electron transfer (PeT) is commonly used as a trigger to modulate fluorescence in response to changes in the biological environment. PeT-based indicators rely on PeT either into the excited state (acceptor PeT) or out of the excited state (donor PeT). Our group has been developing voltage-sensitive fluorophores (VF dyes) that respond to changes in biological membrane potential (Vm). We hypothesize that the mechanism of voltage sensitivity arises from acceptor PeT (a-PeT) from an electron-rich aniline-containing molecular wire into the excited-state fluorophore, resulting in decreased fluorescence at negative Vm. In this work, we reversed the direction of electron flow to access donor-excited PeT (d-PeT) VF dyes by introducing electron-withdrawing rather than electron-rich molecular wires. VF dyes containing electron-withdrawing groups show voltage-sensitive fluorescence, but with the opposite polarity: hyperpolarizing Vm now gives fluorescence increases. We used a combination of computation and experiment to design and synthesize five d-PeT VF targets, two of which are voltage-sensitive.
- Published
- 2022