INTERACTION OF PYRYLIUM DYE WITH SELF-COMPLEMENTARY DNA OLIGOMER AS STUDIED BY H-1-NMR SPECTROSCOPY

Interaction of 2-methyl-4,6-bis-(4-N,N-dimethylaminophenyl) pyrylium s alt (P2) with [d(CGACGTCG)](2) was investigated by H-1 NMR spectroscop y. The aromatic signals of P2 and the oligomer were shifted to the upf ield by forming the complex, and intermolecular NOEs were also observe d between P2 and the terminal CpG base steps but not between P2 and th e central CpG. These results indicate that P2 binds to the weakly stac king CpG steps in an intercalation manner.