Interrogation of Base Pairing of the Spiroiminodihydantoin Diastereomers Using the α-Hemolysin Latch.

ABSTRACT: Spiroiminodihydantoin (Sp) is a hyperoxidized form of guanine (G) resulting from oxidation by reactive oxygen species. The lesion is highly mutagenic, and the stereocenter renders the two isomers with distinct behaviors in chemical, spectroscopic, enzymatic, and computational studies. In this work, the α-hemolysin (αHL) latch sensing zone was employed to investigate the base pairing properties of the Sp diastereomers embedded in a double-stranded DNA. Duplexes containing (S)-Sp consistently gave deeper current blockage, and a baseline resolution of ∼0.8 pA was achieved between (S)-Sp:G and (R)-Sp:G base pairs. Ion fluxes were generally more hindered when Sp was placed opposite pyrimidines. Analysis of the current noise of blockade events further provided dynamics information about the Sp-c

SUBMITTER: Zeng T 

PROVIDER: S-EPMC5440229 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature