Threading DNA Through a Nanometer-Scale Pore: Biophysical and Biotechnological Applications
Abstract
With the goal of developing technologies for biomedical applications (e.g. antiviral treatments, targeted genetic therapies, analyte sensing, and ultra-rapid DNA sequencing), we are studying the mechanism by which DNA is transported through a nanometer-scale pore. Individual molecules of single-stranded DNA (ssDNA) can be detected and characterized as they are driven electrophoretically through a single Staphylococcus aureus alpha-hemolysin (alpha-HL) ion channel. We recently demonstrated that the ability of ssDNA to partition into the pore depends on the side to which the polymer is added and on the magnitude of the applied potential. These results are consistent with the alpha-HL channel’s crystal structure and are providing insight into the physics of DNA transport through a nanopore. We are also researching methods for using ion channels as components of analyte sensors. Using the alpha-HL channel and ssDNA as a model system, we demonstrated an analyte sensing technology based on a single nanopore and pore-permeant polymers. Instead of affixing an analyte binding site to the channel, it is covalently attached to a polymer that is initially free in solution. The binding of analyte to the polymer alters the ability of the polymer to thread into or through the pore. This system can simultaneously quantitate multiple analytes in real-time. Finally, we demonstrate that the signal produced by the transport of individual ssDNA molecules through the alpha-HL channel depends on which end of the channel the polymer enters.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2001
- Bibcode:
- 2001APS..MARG23007K