Relationships between 31P Chemical Shift Tensors and Conformation of Nucleic Acid Backbone: A DFT Study
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- 作者：Jana P
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- 刊名：Journal of Physical Chemistry B
- 出版年：2007
- 出版时间：March 15, 2007
- 年：2007
- 卷：111
- 期：10
- 页码：2658 - 2667
- 全文大小：743K
- 年卷期：v.111,no.10(March 15, 2007)
- ISSN：1520-5207
文摘
Density functional theory (DFT) has been applied to study the conformational dependence of 31P chemicalshift tensors in B-DNA. The gg and gt conformations of backbone phosphate groups representing BI- andBII-DNA have been examined. Calculations have been carried out on static models of dimethyl phosphate(dmp) and dinucleoside-3',5'-monophosphate with bases replaced by hydrogen atoms in vacuo as well as inan explicit solvent. Trends in 31P chemical shift anisotropy (CSA) tensors with respect to the backbone torsionangles 
, 
, 
, and 
are presented. Although these trends do not change qualitatively upon solvation,quantitative changes result in the reduction of the chemical shift anisotropy. For and in the range from270
to 330 and from 240 to 300, respectively, the 
22 and 33 principal components vary within as muchas 30 ppm, showing a marked dependence on backbone conformation. The calculated 31P chemical shifttensor principal axes deviate from the axes of O-P-O bond angles by at most 5. For solvent models, ourresults are in a good agreement with experimental estimates of relative gg and gt isotropic chemical shifts.Solvation also brings the theoretical iso of the gg conformation closer to the experimental gg data of bariumdiethyl phosphate.
, , , and are presented. Although these trends do not change qualitatively upon solvation,quantitative changes result in the reduction of the chemical shift anisotropy. For and in the range from270 to 330 and from 240 to 300, respectively, the 22 and 33 principal components vary within as muchas 30 ppm, showing a marked dependence on backbone conformation. The calculated 31P chemical shifttensor principal axes deviate from the axes of O-P-O bond angles by at most 5. For solvent models, ourresults are in a good agreement with experimental estimates of relative gg and gt isotropic chemical shifts.Solvation also brings the theoretical iso of the gg conformation closer to the experimental gg data of bariumdiethyl phosphate.