ABSTRACT
Signal transmission in neurons goes along with changes in the transmembrane potential. To report them, different approaches including optical voltage-sensing dyes and genetically encoded voltage indicators have evolved. Here, we present a DNA nanotechnology-based system. Using DNA origami, we incorporate and optimize different properties such as membrane targeting and voltage sensing modularly. As a sensing unit, we use a hydrophobic red dye anchored to the membrane and an anionic green dye at the DNA connecting the DNA origami and the membrane dye anchor. Voltage-induced displacement of the anionic donor unit is read out by changes of Fluorescence Resonance Energy Transfer (FRET) of single sensors attached to liposomes. They show a FRET change of ∼5% for ΔΨ=100 mV and allow adapting the potential range of highest sensitivity. Further, the working mechanism is rationalized by molecular dynamics simulations. Our approach holds potential for the application as non-genetically encoded sensors at membranes.
Competing Interest Statement
The authors have declared no competing interest.
ABBREVIATIONS
- GEVI
- Genetically Encoded Voltage Indicator;
- FRET
- Fluorescence Resonance Energy Transfer;
- ssDNA
- single-stranded DNA;
- MD
- Molecular Dynamic;
- TIRF
- Total Internal Reflection Fluorescence;
- dsDNA
- double-stranded DNA;
- smFRET
- single-molecule FRET;
- ALEx
- Alternating Laser Excitation;
- PR
- Proximity Ratio;
- SEM
- Standard Error of the Mean;
- REUS
- Replica Exchange Umbrella Sampling.
