Unzipping kinetics of double-stranded DNA in a nanopore.
We studied the unzipping of single molecules of double-stranded DNA by pulling one of their two strands through a narrow protein pore. Polymerase chain reaction analysis yielded the first direct proof of DNA unzipping in such a system. The time to unzip each molecule was inferred from the ionic current signature of DNA traversal. The distribution of times to unzip under various experimental conditions fit a simple kinetic model. Using this model, we estimated the enthalpy barriers to unzipping and the effective charge of a nucleotide in the pore, which was considerably smaller than previously assumed.
Sauer-Budge
Alexis F
AF
Biophysics Program, Harvard University, Cambridge, MA 02138, USA.
Nyamwanda
Jacqueline A
JA
Lubensky
David K
DK
Branton
Daniel
D
D004247:DNA / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000737:chemistry; D007700:Kinetics; D008954:Models, Biological; D036103:Nanotechnology / Q000379:methods*; D009841:Oligonucleotides / Q000138:chemical synthesis / Q000737:chemistry; D016133:Polymerase Chain Reaction; D014178:Translocation, Genetic
D004277:DNA, Single-Stranded; D009841:Oligonucleotides; D004247:DNA