Hydrogen bond resonances in H2O and carbon-bound base proton peaks in D2O are used to monitori the melting of the CpCpGpG helical duplex in 1.0 M NaCl. At O° C in H2O the low field spectrum consists of resonances at 13.18 and 12.45 ppm from DSS due to the hydrogen bonded N-1 protons of the guanosines of the exterior and interior base pairs, respectively. These values are consistent with predictions based on ring current effects expected for an RNA-11 helix. The chemical shifts of the H-8 and H-6 protons of both the interior and exterior bases show highly co-operative melting transitions and exhibit the same midpoint of 51 ± 2° C.
|Original language||English (US)|
|Number of pages||6|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Dec 23 1974|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology