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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
Author(s) -
Dairaku Takenori,
Furuita Kyoko,
Sato Hajime,
Šebera Jakub,
Nakashima Katsuyuki,
Kondo Jiro,
Yamanaka Daichi,
Kondo Yoshinori,
Okamoto Itaru,
Ono Akira,
Sychrovský Vladimír,
Kojima Chojiro,
Tanaka Yoshiyuki
Publication year - 2016
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201603048
Subject(s) - cytosine , crystallography , chemistry , base pair , nuclear magnetic resonance spectroscopy , stereochemistry , nucleobase , nmr spectra database , isomerization , metal , dna , spectral line , physics , biochemistry , organic chemistry , astronomy , catalysis
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 (−NH 2 ), 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.