Portal de Periódicos da CAPES

Enhanced translocation of single DNA molecules through α-hemolysin nanopores by manipulation of internal charge

2008; National Academy of Sciences; Volume: 105; Issue: 50 Linguagem: Inglês

10.1073/pnas.0808296105

1091-6490

Giovanni Maglia, Marcela Rincón-Restrepo, Ellina Mikhailova, Hagan Bayley,

Advanced biosensing and bioanalysis techniques

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.