Spectral density mapping at multiple magnetic fields suitable for C-13 NMR relaxation studies

Investor logo
Investor logo
Investor logo

Warning

This publication doesn't include Faculty of Medicine. It includes Central European Institute of Technology. Official publication website can be found on muni.cz.

Authors

KADEŘÁVEK Pavel ZAPLETAL Vojtěch FIALA Radovan SRB Pavel PADRTA Petr PAVLÍKOVÁ PŘECECHTĚLOVÁ Jana ŠOLTÉSOVÁ Mária KOWALEWSKI Jozef WIDMALM Göran CHMELÍK Josef SKLENÁŘ Vladimír ŽÍDEK Lukáš

Year of publication 2016
Type Article in Periodical
Magazine / Source Journal of Magnetic Resonance
MU Faculty or unit

Central European Institute of Technology

Citation
Web http://www.sciencedirect.com/science/article/pii/S1090780716001191
Doi http://dx.doi.org/10.1016/j.jmr.2016.02.016
Field Biochemistry
Keywords Nuclear magnetic resonance; Relaxation; Spectral density function; Magnetic field; Nucleic acids; Carbohydrates
Description Standard spectral density mapping protocols, well suited for the analysis of N-15 relaxation rates, introduce significant systematic errors when applied to C-13 relaxation data, especially if the dynamics is dominated by motions with short correlation times (small molecules, dynamic residues of macromolecules). A possibility to improve the accuracy by employing cross-correlated relaxation rates and on measurements taken at several magnetic fields has been examined. A suite of protocols for analyzing such data has been developed and their performance tested. Applicability of the proposed protocols is documented in two case studies, spectral density mapping of a uniformly labeled RNA hairpin and of a selectively labeled disaccharide exhibiting highly anisotropic tumbling. Combination of auto- and cross-correlated relaxation data acquired at three magnetic fields was applied in the former case in order to separate effects of fast motions and conformational or chemical exchange. An approach using auto-correlated relaxation rates acquired at five magnetic fields, applicable to anisotropically moving molecules, was used in the latter case. The results were compared with a more advanced analysis of data obtained by interpolation of auto-correlated relaxation rates measured at seven magnetic fields, and with the spectral density mapping of cross-correlated relaxation rates. The results showed that sufficiently accurate values of auto- and cross-correlated spectral density functions at zero and C-13 frequencies can be obtained from data acquired at three magnetic fields for uniformly C-13-labeled molecules with a moderate anisotropy of the rotational diffusion tensor. Analysis of auto-correlated relaxation rates at five magnetic fields represents an alternative for molecules undergoing highly anisotropic motions. (C) 2016 Elsevier Inc. All rights reserved.
Related projects:

You are running an old browser version. We recommend updating your browser to its latest version.

More info