Molecular force spectroscopy with a DNA origami-based nanoscopic force clamp

Area of Science:

• Biophysics
• Molecular Biology
• Nanotechnology

Background:

• Traditional single-molecule force measurement techniques (AFM, optical/magnetic tweezers) have limitations in data throughput and require physical connections.
• Investigating forces in biological systems is crucial for understanding molecular mechanisms and cellular processes.

Purpose of the Study:

• To introduce a novel, self-assembled DNA nanoscopic force clamp for autonomous and massively parallelized force measurements.
• To investigate the effects of piconewton-range tension on molecular systems, specifically DNA bending induced by TATA-binding protein.

Main Methods:

• Utilized DNA origami structures with single-stranded DNA sections acting as entropic springs to generate controlled tension.
• Employed single-molecule Förster resonance energy transfer (smFRET) to monitor conformational transitions of molecular systems under tension.
• Used Holliday junction conformer switching as a benchmark and studied TATA-binding protein-induced DNA bending.

Main Results:

• Demonstrated the capability of the DNA nanoscopic force clamp to apply controlled tension in the low piconewton range.
• Observed that DNA bending induced by TATA-binding protein is suppressed at tensions above 10 piconewtons.
• Validated the DNA nanoscopic force clamp as a viable tool for studying mechanosensitivity in biological systems.

Conclusions:

• The developed DNA nanoscopic force clamp offers a powerful, high-throughput alternative for investigating forces in biological systems.
• The findings provide evidence for mechanosensitivity in gene regulation, highlighting the role of DNA bending under tension.
• This technology opens new avenues for studying molecular mechanics and the physical underpinnings of biological processes.