Increasing the sensitivity of NMR diffusion measurements by paramagnetic longitudinal relaxation enhancement, with application to ribosomeā??nascent chain complexes
Increasing the sensitivity of NMR diffusion measurements by paramagnetic longitudinal relaxation enhancement, with application to ribosomeā??nascent chain complexes
The translational diffusion of macromolecules can be examined non-invasively by stimulated echo (STE) NMR experiments to accurately determine their molecular sizes. These measurements can be important probes of intermolecular interactions and protein folding and unfolding, and are crucial in monitoring the integrity of large macromolecular assemblies such as ribosomeā??nascent chain complexes (RNCs). However, NMR studies of these complexes can be severely constrained by their slow tumbling, low solubility (with maximum concentrations of up to 10Ā*Ī¼M), and short lifetimes resulting in weak signal, and therefore continuing improvements in experimental sensitivity are essential. Here we explore the use of the paramagnetic longitudinal relaxation enhancement (PLRE) agent NiDO2A on the sensitivity of 15N XSTE and SORDID heteronuclear STE experiments, which can be used to monitor the integrity of these unstable complexes. We exploit the dependence of the PLRE effect on the gyromagnetic ratio and electronic relaxation time to accelerate recovery of 1H magnetization without adversely affecting storage on N z during diffusion delays or introducing significant transverse relaxation line broadening. By applying the longitudinal relaxation-optimized SORDID pulse sequence together with NiDO2A to 70S Escherichia coli ribosomes and RNCs, NMR diffusion sensitivity enhancements of up to 4.5-fold relative to XSTE are achieved, alongside ~1.9-fold improvements in two-dimensional NMR sensitivity, without compromising the sample integrity. We anticipate these results will significantly advance the use of NMR to probe dynamic regions of ribosomes and other large, unstable macromolecular assemblies.
[NMR paper] Heteronuclear Transverse and Longitudinal Relaxation in AX4 Spin Systems: Application to 15N Relaxations in 15NH4+
Heteronuclear Transverse and Longitudinal Relaxation in AX4 Spin Systems: Application to 15N Relaxations in 15NH4+
Publication date: Available online 28 June 2014
Source:Journal of Magnetic Resonance</br>
Author(s): Nicolas D. Werbeck , D. Flemming Hansen</br>
The equations that describe the time-evolution of transverse and longitudinal 15N magnetisations in tetrahedral ammonium ions, 15NH4 +, are derived from the Bloch-Wangsness-Redfield density operator relaxation theory. It is assumed that the relaxation of the spin-states is dominated by (1) the intra-molecular...
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06-29-2014 02:00 AM
[NMR paper] Sensitivity and resolution enhancement of oriented solid-state NMR: Application to membrane proteins.
Sensitivity and resolution enhancement of oriented solid-state NMR: Application to membrane proteins.
Related Articles Sensitivity and resolution enhancement of oriented solid-state NMR: Application to membrane proteins.
Prog Nucl Magn Reson Spectrosc. 2013 Nov;75:50-68
Authors: Gopinath T, Mote KR, Veglia G
Abstract
Oriented solid-state NMR (O-ssNMR) spectroscopy is a major technique for the high-resolution analysis of the structure and topology of transmembrane proteins in native-like environments. Unlike magic angle spinning (MAS)...
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10-29-2013 08:21 PM
[NMR paper] Longitudinal Relaxation Enhancement in (1) H NMR Spectroscopy of Tissue Metabolites via Spectrally Selective Excitation.
Longitudinal Relaxation Enhancement in (1) H NMR Spectroscopy of Tissue Metabolites via Spectrally Selective Excitation.
http://www.bionmr.com//www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--media.wiley.com-assets-2250-98-WileyOnlineLibrary-Button_120x27px_FullText.gif Related Articles Longitudinal Relaxation Enhancement in (1) H NMR Spectroscopy of Tissue Metabolites via Spectrally Selective Excitation.
Chemistry. 2013 Sep 3;
Authors: Shemesh N, Dumez JN, Frydman L
Abstract
Nuclear magnetic resonance spectroscopy is governed by...
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Sensitivity and Resolution Enhancement of Oriented Solid-State NMR: Application to Membrane Proteins
Sensitivity and Resolution Enhancement of Oriented Solid-State NMR: Application to Membrane Proteins
Publication date: Available online 12 August 2013
Source:Progress in Nuclear Magnetic Resonance Spectroscopy</br>
Author(s): T. Gopinath , Kaustubh R. Mote , Gianluigi Veglia</br>
Oriented solid-state NMR (O-ssNMR) spectroscopy is a major technique for the high-resolution analysis of the structure and topology of transmembrane proteins in native-like environments. Unlike magic angle spinning (MAS) techniques, O-ssNMR spectroscopy requires membrane protein...
Paramagnetic relaxation enhancement to improve sensitivity of fast NMR methods: application to intrinsically disordered proteins
Paramagnetic relaxation enhancement to improve sensitivity of fast NMR methods: application to intrinsically disordered proteins
Abstract We report enhanced sensitivity NMR measurements of intrinsically disordered proteins in the presence of paramagnetic relaxation enhancement (PRE) agents such as Ni2+-chelated DO2A. In proton-detected 1H-15N SOFAST-HMQC and carbon-detected (H-flip)13CO-15N experiments, faster longitudinal relaxation enables the usage of even shorter interscan delays. This results in higher NMR signal intensities per units of experimental time, without adverse line...
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10-21-2011 10:04 PM
[Question from NMRWiki Q&A forum] Relaxation editing vr paramagnetic relaxation enhancement experiments - 13C CP-MAS NM
Relaxation editing vr paramagnetic relaxation enhancement experiments - 13C CP-MAS NMR
I am a beginner in NMR spectroscopy and I would like to learn more about relaxation editing experiments vs PRE. A colleague of mine is doing the 13C CP-MAS NMR experim. and he using cellulose II powder, regenerated cellulose and milled reg cellulose. We are interested in C4 resonance of cellulose II, good resolved resonance, to better understand the supramolecular structure of cellulose II. As experiments: long relaxation experiments - PRE with aqueous CuSO4 solution of certain concentration, does the...
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10-15-2010 05:16 PM
[Question from NMRWiki Q&A forum] Does anyone know something about paramagnetic relaxation enhancement (PRE)?
Does anyone know something about paramagnetic relaxation enhancement (PRE)?
Does anyone know something about paramagnetic relaxation enhancement (PRE)? i would like to try this method on my cellulose materials. What info can you take out of it? Thank you very much.
Check if somebody has answered this question on NMRWiki QA forum