Effect of an Electrolyte Cation on Detecting DNA Damage with the Latch Constriction of ?-Hemolysin.

ABSTRACT: The effect of an electrolyte cation on the unzipping of furan-containing double-stranded DNA in an ?-hemolysin (?HL) nanopore is described. The current through an open ?HL channel increases in proportion to the ion mobility. However, the ionic current measured during residence of a DNA duplex inside of the protein pore shows a more complex dependence on the choice of cation, indicating that the current measured during DNA residence in the pore is modulated by the specific interactions of the cations with the DNA and/or ?HL. The residence time (stability) of the DNA duplex inside of the pore prior to unzipping is also highly dependent on the cation, in striking contrast to the small variation in duplex stability (as measured by the melting temperature) in bulk electrolyte solution. A missing base in DNA can be detected in the latch region of ?HL with optimal current resolution in RbCl, while optimal time resolution is possible in LiCl.

SUBMITTER: Johnson RP 

PROVIDER: S-EPMC4226304 | biostudies-literature | 2014 Nov

REPOSITORIES: biostudies-literature