Translocation of a single-stranded DNA molecule through genetically engineered -hemolysin channels with positively charged walls is studied. It is predicted that transport properties of such channels are dramatically different from neutral wild-type -hemolysin channels. We assume that the wall charges compensate a fraction of the bare charge of the DNA piece residing in the channel. Our predictions are as follows. (i) At small concentration of salt the blocked ion current decreases with . (ii) The effective charge of the DNA piece, which is very small at (neutral channel) grows with and at reaches . (iii) The rate of DNA capture by the channel grows exponentially with . Our theory is also applicable to translocation of a double-stranded DNA molecular in narrow solid state nanopores with positively charged walls.
- Received 13 March 2008
©2008 American Physical Society