31P Chemical Shift Tensors for Canonical and Non-Canonical Nucleic Acid Conformations: DFT Calculations and NMR Implications.
| Authors | |
|---|---|
| Year of publication | 2008 |
| Type | Article in Periodical |
| Magazine / Source | Journal of Physical Chemistry B |
| MU Faculty or unit | |
| Citation | |
| Field | Physical chemistry and theoretical chemistry |
| Keywords | NMR chemical shift tensor 31P nucleic acids RDC |
| Description | 31P chemical shift anisotropy (CSA) tensors have been calculated for a set of selected DNA and RNA backbone conformations using density functional theory. The set includes canonical A-RNA, A-DNA, BI-DNA, BII-DNA, ZI-DNA, ZII-DNA as well as four A-RNA-type, seven non-A-RNA-type, and three non-canonical DNA conformations. Hexahydrated dimethyl phosphate has been employed as a model. The 31P chemical shift tensors obtained are discussed in terms of similarities in the behavior observed for gauche-gauche (gg) and gauche-trans (gt) conformations around the PO bonds. We show that torsion angles are major determinants of the isotropic chemical shift. The 31P CSA tensors exhibit considerable variations resulting in large spans of its components. We examine the consequences of the CSA variations for predicting the chemical shift changes upon partial alignment and on the values of CSA order parameters extracted from the analysis of 31P NMR relaxation data. |
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