Anomeric-aromatic portion of the 500-Mhz
1H NOESY spectrum at 10°C of the Adriamycin-DNA adduct
mediated by Tris/Fe(III)/DTT. The connectivity patterns between
anomeric and aromatic DNA protons are correlated by color to the
schematic Adriamycin-DNA adduct shown above. The c-strand is shown in
blue, whereas the n-strand is depicted in black and red. The NOESY
connectivity pattern between DNA protons is interrupted between the
C4pA5 step of the c-strand and the T8pG9 step of the n-strand,
indicating intercalation of the Adriamycin chromophore at this point
and covalent attachment to G3. Connectivity along the c-strand is
completed by contacts between the aromatic protons C4H6 and A5H8 to the
Adriamycin-H1′ carbohydrate proton. The box representing connectivity
between the protons G9H8, G9H1′, C10H6, and C10H5, shown in green, was
a characteristic feature of all observed Adriamycin-DNA spectra of the
type
d[(AT)nGC(AT)n]2.
Residual unlabeled cross-peaks represent small amounts of unreacted DNA
that was coexcised from the gel with the adduct.