a 2007

P-31 Chemical Shift Tensors in RNA and DNA Backbone. A DFT Study of Conformational Dependence and Its Implications for NMR Studies.

PŘECECHTĚLOVÁ, Jana, Petr PADRTA, Markéta MUNZAROVÁ and Vladimír SKLENÁŘ

Basic information

Original name

P-31 Chemical Shift Tensors in RNA and DNA Backbone. A DFT Study of Conformational Dependence and Its Implications for NMR Studies.

Name in Czech

P-31 Chemicke posuny v pateri RNA a DNA. DFT studium konformacni zavislosti a jeji dusledky pro NMR aplikace.

Authors

Edition

43rd Symposium on Theoretical Chemistry: Large, Non-Biological Systems, 2007

Other information

Language

English

Type of outcome

Konferenční abstrakt

Field of Study

10403 Physical chemistry

Country of publisher

Czech Republic

Confidentiality degree

není předmětem státního či obchodního tajemství

Organization unit

Faculty of Science

Keywords in English

DFT calculations; P-31 chemical shifts; NMR ; DNA; RNA

Tags

International impact
Změněno: 27/6/2008 13:36, Mgr. Jana Pavlíková Přecechtělová, Ph.D.

Abstract

V originále

P-31 chemical shift anisotropy (CSA) tensors in DNA and RNA backbone conformations have been studied at the DFT level using hexahydrated dimethyl phosphate as a model. The set of conformations inspected includes canonical A-RNA, A-DNA, B-DNA, and Z-DNA as well as non-canonical structures of both DNA and RNA. The P-31 chemical shift tensors obtained are discussed in terms of characteristics common for gauche-gauche (gg) and gauche-trans-conformations (gt) around the P-O bonds. Our calculations reveal a dominant effect of backbone torsion angles alpha and zeta on the isotropic chemical shift delta_iso and the delta^CSA_11 component of the traceless chemical shift tensor that results in separated ranges of both delta_iso and delta^CSA_11 for the gg- and gt-conformers, respectively. No such clear distinction between the two conformation types has been found for components delta^CSA_22 and delta^CSA_33, which is attributed to their different directional properties in the molecule favoring the influence of coupled changes in all torsion angles (alpha, zeta, beta, epsilon). The values of P-31 CSA tensor components display large spans of 16 ppm for delta^CSA_11 and ~22 ppm for delta^CSA_22 and delta^CSA_33. The considerable variations in tensor components among conformations has important implications for experimental P-31 NMR studies. We examine the effect on the predicted values of chemical shift changes upon partial alignment as well as on CSA order parameters derived from relaxation measurements. The goal of the study is to assess the consequences of using a uniform P-31 CSA tensor for nucleic acid structure refinement and for the interpretation of P-31 NMR relaxation data.

In Czech

P-31 chemical shift anisotropy (CSA) tensors in DNA and RNA backbone conformations have been studied at the DFT level using hexahydrated dimethyl phosphate as a model. The set of conformations inspected includes canonical A-RNA, A-DNA, B-DNA, and Z-DNA as well as non-canonical structures of both DNA and RNA. The P-31 chemical shift tensors obtained are discussed in terms of characteristics common for gauche-gauche (gg) and gauche-trans-conformations (gt) around the P-O bonds. Our calculations reveal a dominant effect of backbone torsion angles alpha and zeta on the isotropic chemical shift delta_iso and the delta^CSA_11 component of the traceless chemical shift tensor that results in separated ranges of both delta_iso and delta^CSA_11 for the gg- and gt-conformers, respectively. No such clear distinction between the two conformation types has been found for components delta^CSA_22 and delta^CSA_33, which is attributed to their different directional properties in the molecule favoring the influence of coupled changes in all torsion angles (alpha, zeta, beta, epsilon). The values of P-31 CSA tensor components display large spans of 16 ppm for delta^CSA_11 and ~22 ppm for delta^CSA_22 and delta^CSA_33. The considerable variations in tensor components among conformations has important implications for experimental P-31 NMR studies. We examine the effect on the predicted values of chemical shift changes upon partial alignment as well as on CSA order parameters derived from relaxation measurements. The goal of the study is to assess the consequences of using a uniform P-31 CSA tensor for nucleic acid structure refinement and for the interpretation of P-31 NMR relaxation data.

Links

GD204/03/H016, research and development project
Name: Strukturní biofyzika makromolekul
Investor: Czech Science Foundation, Structural biophysics of macromolecules
LC06030, research and development project
Name: Biomolekulární centrum
Investor: Ministry of Education, Youth and Sports of the CR, Biomolecular centre
MSM0021622413, plan (intention)
Name: Proteiny v metabolismu a při interakci organismů s prostředím
Investor: Ministry of Education, Youth and Sports of the CR, Proteins in metabolism and interaction of organisms with the environment