Hm. Kang et Se. Rokita, SITE-SPECIFIC AND PHOTOINDUCED ALKYLATION OF DNA BY A DIMETHYLANTHRAQUINONE-OLIGODEOXYNUCLEOTIDE CONJUGATE, Nucleic acids research, 24(20), 1996, pp. 3896-3902
A dialkyl-substituted anthraquinone derivative was synthesized and lig
ated to a sequence-directing oligodeoxynucleotide to examine its effic
iency and specificity for cross-linking to complementary sequences of
DNA. The anthraquinone appendage stabilized spontaneous hybridization
of the target and probe sequences through non-covalent interactions, a
s indicated by thermal denaturation studies. Covalent modification of
the target was induced by exposure to near UV light (lambda > 335 nm)
to generate cross-linked duplexes in yields as great as 45%. Reaction
was dependent on the first unpaired nucleotide extended beyond the dup
lex formed by association of the target and probe. A specificity of C
> T > A approximate to G was determined for modification at this posit
ion. The overall site and nucleotide selectivity seems to originate fr
om the chemical requirements of cross-linking and does not likely refl
ect the dominant solution structure of the complex prior to irradiatio
n.