Applications of tritium NMR to macromolecules: a study of two nucleic acid molecules.

We have tritium labeled two nucleic acid molecules, an 8 kDa DNA oligomer and a 20 kDa 'hammer-head' RNA for tritium NMR investigations. The DNA sequence studied has been previously used in homonuclear studies of DNA-bound water molecules and tritium NMR was expected to facilitate these investigations by eliminating the need to suppress the water resonance in tritium-detected 3H-1H NOESY experiments. We observed the anticipated through-space interactions found in B-form DNA in the NOESY experiments and an unexpected 'antiphase' cross-peak at the water frequency.

Effect of adenine methylation on the structure and dynamics of TpA steps in DNA: NMR structure determination of [d(CGAGGTTTAAACCTCG)]2 and its A9-methylated derivative at 750 MHz.

At TpA steps in DNA, the adenine base experiences exceptionally large amplitude (20 degrees-50 degrees) and slow (10 ms-1 microsecond) motion [Kennedy et al. (1993) Biochemistry 32, 8022-8035] which has been correlated with transitions between multiple conformational states [Lefevre et al. (1985) FEBS Lett.

[2-3H]ATP synthesis and 3H NMR spectroscopy of enzyme-nucleotide complexes: ADP and ADP.Vi bound to myosin subfragment 1.

The synthesis of [2-3H]ATP with specific activity high enough to use for 3H NMR spectroscopy at micromolar concentrations was accomplished by tritiodehalogenation of 2-Br-ATP. ATP with greater than 80% substitution at the 2-position and negligible tritium levels at other positions had a single 3H NMR peak at 8.20 ppm in 1D spectra obtained at 533 MHz.