Regensburg 2007 – scientific programme
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BP: Fachverband Biologische Physik
BP 26: Poster Session II
BP 26.37: Poster
Thursday, March 29, 2007, 17:00–19:30, Poster B
Unzipping DNA in a biological nanopore — •U. F. Keyser1,2, N. M. Wennersbusch1, N. H. Dekker1, and C. Dekker1 — 1Kavli Institute of Nanoscience, Delft University of Technology, The Netherlands — 2Institut für Experimentelle Physik I, Universität Leipzig, Germany
Biological nanopores like protein toxins from bacteria can be used to analyze the structural properties of nucleic acids like DNA or RNA or proteins. We assemble the alpha-hemolysin nanopore, extracted from staphylococcus aureus, in a artificial lipid membrane. Applying a membrane potential allows driving DNA through the nanopore. Since only single-stranded DNA can pass the pore unhindered we use it to unzip double-stranded DNA constructs consisting of two hybridized strands. Varying the temperature and applied voltage we extract the unzipping time using a simple model. The unzipping time is consistent with values from the literature. We show that the unzipped strand can remain for up to several ms in the hemolysin prepore before it also translocates or leaves the nanopore. Varying the sequence of the DNA has little influence on the results. We discuss different possibilities for interaction between the nanopore and the passing DNA strand.