Small amphiphilic DNA for programmable transmembrane signaling and amplification.

Area of Science:

• Biotechnology
• Nanotechnology
• Molecular Biology

Background:

• Transmembrane proteins like GPCRs signal across lipid bilayers via allosteric mechanisms.
• Engineering DNA nanostructures for transmembrane signaling faces challenges due to DNA's hydrophilicity and membrane's hydrophobicity.

Purpose of the Study:

• To develop a DNA-based system for transmembrane signal transduction and intracellular target detection.
• To overcome the limitations of DNA-membrane incompatibility for biosensing applications.

Main Methods:

• Designed amphiphilic DNA hairpins (HALOS) with cholesterol anchors for transmembrane integration.
• Utilized strand invasion and conformational switching for signal transduction across lipid bilayers.
• Combined HALOS with isothermal hybridization chain reaction (HCR) for signal amplification.

Main Results:

• Demonstrated successful DNA hybridization across lipid membranes, challenging previous assumptions.
• MD simulations confirmed cholesterol tags stabilize DNA structures within the bilayer.
• Achieved nanomolar sensitivity for intracellular nucleic acid detection with amplified fluorescent reporting.

Conclusions:

• HALOS enables transmembrane signal transduction using DNA nanostructures.
• This platform facilitates lysis-free intracellular target detection and reporting in synthetic vesicles and live cells.
• HALOS expands DNA nanotechnology for membrane integration, with applications in diagnostics and synthetic biology.