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09:43
Fine-tuning the Size and Minimizing the Noise of Solid-state Nanopores
Published on: October 31, 2013
Electrophoretic force on a protein-coated DNA molecule in a solid-state nanopore
Adam R Hall1, Stijn van Dorp, Serge G Lemay
1Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
Nano Letters
|September 29, 2009
Summary
Solid-state nanopores with optical tweezers reveal that RecA protein-coated DNA experiences significantly higher electrophoretic forces. This technique enables precise measurement of forces on DNA-bound proteins, advancing screening device potential.
Area of Science:
- Biophysics
- Nanotechnology
- Molecular Biology
Background:
- RecA protein plays a crucial role in DNA repair and recombination.
- Understanding protein-DNA interactions is vital for molecular biology and nanotechnology.
- Force spectroscopy is a key technique for probing molecular interactions.
Purpose of the Study:
- To investigate the forces on RecA-coated DNA using solid-state nanopores and optical tweezers.
- To quantify the electrophoretic and hydrodynamic forces acting on RecA-DNA filaments.
- To explore the potential of solid-state nanopores for analyzing protein-DNA complexes.
Main Methods:
- Utilized solid-state nanopores combined with optical tweezers for force spectroscopy.
- Performed measurements on DNA molecules coated with RecA proteins.
- Analyzed changes in conductance and electrophoretic forces at varying salt concentrations.
Main Results:
- RecA-DNA filaments exhibited 2-4 times greater electrophoretic force compared to uncoated DNA.
- Electrophoretic force increased with decreasing salt concentration.
- Conductance changes at the nanopore entrance varied with salt concentration, allowing apparent charge extraction.
Conclusions:
- Solid-state nanopores are effective for local force probing of DNA-bound proteins.
- A quantitative model accurately describes the observed electrophoretic and hydrodynamic forces.
- Combining conductance measurements with force spectroscopy enhances solid-state nanopore screening capabilities.
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