Impact of nucleic acid self-alignment in a strong magnetic field on the interpretation of indirect spin-spin interactions

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388963%3A_____%2F16%3A00458986" target="_blank" >RIV/61388963:_____/16:00458986 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216224:14740/16:00087769

Výsledek na webu

<a href="http://link.springer.com/article/10.1007/s10858-015-0005-x" target="_blank" >http://link.springer.com/article/10.1007/s10858-015-0005-x</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s10858-015-0005-x" target="_blank" >10.1007/s10858-015-0005-x</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Impact of nucleic acid self-alignment in a strong magnetic field on the interpretation of indirect spin-spin interactions

Popis výsledku v původním jazyce

Heteronuclear and homonuclear direct (D) and indirect (J) spin-spin interactions are important sources of structural information about nucleic acids (NAs). The Hamiltonians for the D and J interactions have the same functional form; thus, the experimentally measured apparent spin-spin coupling constant corresponds to a sum of J and D. In biomolecular NMR studies, it is commonly presumed that the dipolar contributions to Js are effectively canceled due to random molecular tumbling. However, in strong magnetic fields, such as those employed for NMR analysis, the tumbling of NA fragments is anisotropic because the inherent magnetic susceptibility of NAs causes an interaction with the external magnetic field. This motional anisotropy is responsible for non-zero D contributions to Js. Here, we calculated the field-induced D contributions to 33 structurally relevant scalar coupling constants as a function of magnetic field strength, temperature and NA fragment size. We identified two classes of Js, namely (1)J(CH) and (3)J(HH) couplings, whose quantitative interpretation is notably biased by NA motional anisotropy. For these couplings, the magnetic field-induced dipolar contributions were found to exceed the typical experimental error in J-coupling determinations by a factor of two or more and to produce considerable over-or underestimations of the J coupling-related torsion angles, especially at magnetic field strengths >12 T and for NA fragments longer than 12 bp. We show that if the non-zero D contributions to J are not properly accounted for, they might cause structural artifacts/bias in NA studies that use solution NMR spectroscopy.

Název v anglickém jazyce

Impact of nucleic acid self-alignment in a strong magnetic field on the interpretation of indirect spin-spin interactions

Popis výsledku anglicky

Heteronuclear and homonuclear direct (D) and indirect (J) spin-spin interactions are important sources of structural information about nucleic acids (NAs). The Hamiltonians for the D and J interactions have the same functional form; thus, the experimentally measured apparent spin-spin coupling constant corresponds to a sum of J and D. In biomolecular NMR studies, it is commonly presumed that the dipolar contributions to Js are effectively canceled due to random molecular tumbling. However, in strong magnetic fields, such as those employed for NMR analysis, the tumbling of NA fragments is anisotropic because the inherent magnetic susceptibility of NAs causes an interaction with the external magnetic field. This motional anisotropy is responsible for non-zero D contributions to Js. Here, we calculated the field-induced D contributions to 33 structurally relevant scalar coupling constants as a function of magnetic field strength, temperature and NA fragment size. We identified two classes of Js, namely (1)J(CH) and (3)J(HH) couplings, whose quantitative interpretation is notably biased by NA motional anisotropy. For these couplings, the magnetic field-induced dipolar contributions were found to exceed the typical experimental error in J-coupling determinations by a factor of two or more and to produce considerable over-or underestimations of the J coupling-related torsion angles, especially at magnetic field strengths >12 T and for NA fragments longer than 12 bp. We show that if the non-zero D contributions to J are not properly accounted for, they might cause structural artifacts/bias in NA studies that use solution NMR spectroscopy.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

CF - Fyzikální chemie a teoretická chemie

OECD FORD obor

—

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2016

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Biomolecular NMR

ISSN

0925-2738

e-ISSN

—

Svazek periodika

64

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

10

Strana od-do

53-62

Kód UT WoS článku

000372168000006

EID výsledku v databázi Scopus

2-s2.0-84957946747