Phosphorus-31 Spin–Spin Coupling Constants: Principles and Applications

A therapeutic aptamer inhibits angiogenesis by specifically targeting the heparin binding domain of VEGF 165

“…However, no Ca 2ϩ dependence was observed in the NMR spectra of the free aptamer or free HBD (data not shown), and the same small change in melting temperature of the aptamer (3°C) was observed upon addition of either Ca 2ϩ or Mg 2ϩ (8) Thus it appears the Ca 2ϩ binding site is formed only in the aptamer-protein complex, and this Ca 2ϩ binding site may contribute to the isoform-specific recognition of the aptamer. 31 P chemical shifts are sensitive to the local environment of phosphates in nucleic acids (21). The HMG box protein SRY bound to its DNA promoter sequence is one of the few proteinnucleic acid systems that have been characterized by 31 P NMR (22).…”

“…This complex shows a 31 P chemical shift dispersion of 2.8 ppm with a number of resonances shifted away from standard DNA duplex 31 P chemical shifts. These nonstandard 31 P chemical shifts can arise from a variety of factors, including salt bridges between Arg or Lys residues and the phosphate groups, intermolecular or intramolecular hydrogen bonding, or metal coordination (21,22,26). A large percentage (10 of 28) of the 31 P resonances in the HBD-aptamer complex have nonstandard chemical shifts (Fig.…”

“…The two additional resonances in the VEGF 164 -aptamer complex were tentatively assigned to the imino proton of U20 (11.61 ppm) in the internal loop of the aptamer and to the amide proton of C57 (11.96 ppm), based on previously published assignments of the receptorbinding domain of VEGF (20). 31 P chemical shifts are a sensitive probe of unusual backbone conformations of oligonucleotides and are especially valuable for studying protein-nucleic acid interactions (21,22). Fig.…”

Hydrogen bonding effects on 31P NMR shielding in the pyrophosphate group of NADPH bound to L. casei dihydrofolate reductase

“…Gorenstein and collaborators [7-lo] have further suggested that the 3'P chemical shifts are also dependent on P-O-C-H torsional angles and that P-O-P bond angle and P-O-C-H torsion angle effects are in fact related phenomena. Molecular orbital calculations for phosphate diester groups have indicated that rotation about the P-O-C-H torsion angle could produce O-P-O bond angle changes and some support for this predictibn was provided by X-ray structural data from some nucleotides wl:h large differences in torsion angle [11,12]. In the NMR studies of the DI-IFRaNADPH complexes, measurements of 3&o.c.w coupling constants allowed the P-O+H, ' torsion angles to be estimated.…”

Two-Dimensional1H and31P NMR Spectra of a Decamer Oligodeoxyribonucleotide Duplex and a Quinoxaline ([MeCys3, MeCys7]TANDEM) Drug Duplex Complex

“…We have noted that 31 P chemical shifts can potentially provide a probe of the conformation of the phosphate ester backbone in nucleic acids and nucleic acid complexes ( 60,64,(76)(77)(78)(79). These studies suggested that the 31 P resonance of a phosphate diester in a g,g or g -,g -conformation should be several ppm upfield of the 31 P signal of an ester in a g,t or t,t conformation (79).…”