The Research of G-Motif Construction and Chirality in Deoxyguanosine Monophosphate Nucleotide Complexes

A detailed understanding of the mismatched base-pairing interactions in DNA will help reveal genetic diseases and provide a theoretical basis for the development of targeted drugs. Here, we utilized mononucleotide fragment to simulate mismatch DNA interactions in a local hydrophobic microenvironment. The bipyridyl-type bridging ligands were employed as a mild stabilizer to stabilize the GG mismatch containing complexes, allowing mismatch to be visualized based on X-ray crystallography. Five single crystals of 2'-deoxyguanosine-5'-monophosphate (dGMP) metal complexes were designed and obtained via the process of self-assembly. Crystallographic studies clearly reveal the details of the supramolecular interaction between mononucleotides and guest intercalators. A novel guanine-guanine base mismatch pattern with unusual (high anti)-(high anti) type of arrangement around the glycosidic angle conformations was successfully constructed. The solution state ¹H-NMR, ESI-MS spectrum studies, and UV titration experiments emphasize the robustness of this g-motif in solution. Additionally, we combined the methods of single-crystal and solution-, solid-state CD spectrum together to discuss the chirality of the complexes. The complexes containing the g-motif structure, which reduces the energy of the system, following the solid-state CD signals, generally move in the long-wave direction. These results provided a new mismatched base pairing, that is g-motif. The interaction mode and full characterizations of g-motif will contribute to the study of the mismatched DNA interaction.