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 …