Enhanced translocation of single DNA molecules through α-hemolysin nanopores by manipulation of internal charge |
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| Authors: | Giovanni Maglia Marcela Rincon Restrepo Ellina Mikhailova Hagan Bayley |
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| Affiliation: | Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom |
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| Abstract: | Both protein and solid-state nanopores are under intense investigation for the analysis of nucleic acids. A crucial advantage of protein nanopores is that site-directed mutagenesis permits precise tuning of their properties. Here, by augmenting the internal positive charge within the α-hemolysin pore and varying its distribution, we increase the frequency of translocation of a 92-nt single-stranded DNA through the pore at +120 mV by ≈10-fold over the wild-type protein and dramatically lower the voltage threshold at which translocation occurs, e.g., by 50 mV for 1 event·s−1·μM−1. Further, events in which DNA enters the pore, but is not immediately translocated, are almost eliminated. These experiments provide a basis for improved nucleic acid analysis with protein nanopores, which might be translated to solid-state nanopores by using chemical surface modification. |
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| Keywords: | DNA sequencing electroosmosis nanopore protein engineering single-molecule detection |
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