Structure Determination of an Ag(I) -Mediated Cytosine-Cytosine Base Pair within DNA Duplex in Solution with (1) H/(15) N/(109) Ag NMR Spectroscopy.
Dairaku, T., Furuita, K., Sato, H., Sebera, J., Nakashima, K., Kondo, J., Yamanaka, D., Kondo, Y., Okamoto, I., Ono, A., Sychrovsky, V., Kojima, C., Tanaka, Y.(2016) Chemistry 22: 13028-13031
- PubMed: 27505707
- DOI: https://doi.org/10.1002/chem.201603048
- Primary Citation of Related Structures:
2RVP - PubMed Abstract:
The structure of an Ag(I) -mediated cytosine-cytosine base pair, C-Ag(I) -C, was determined with NMR spectroscopy in solution. The observation of 1-bond (15) N-(109) Ag J-coupling ((1) J((15) N,(109) Ag): 83 and 84 Hz) recorded within the C-Ag(I) -C base pair evidenced the N3-Ag(I) -N3 linkage in C-Ag(I) -C. The triplet resonances of the N4 atoms in C-Ag(I) -C demonstrated that each exocyclic N4 atom exists as an amino group (-NH2 ), and any isomerization and/or N4-Ag(I) bonding can be excluded. The 3D structure of Ag(I) -DNA complex determined with NOEs was classified as a B-form conformation with a notable propeller twist of C-Ag(I) -C (-18.3±3.0°). The (109) Ag NMR chemical shift of C-Ag(I) -C was recorded for cytidine/Ag(I) complex (δ((109) Ag): 442 ppm) to completed full NMR characterization of the metal linkage. The structural interpretation of NMR data with quantum mechanical calculations corroborated the structure of the C-Ag(I) -C base pair.
Organizational Affiliation:
School of Pharmaceutical Sciences, Ohu University, 31-1 Misumido, Tomita-machi, Koriyama, Fukushima, 963-8611, Japan. t-dairaku@pha.ohu-u.ac.jp.