Publication date: Available online 19 April 2014 Source:Journal of Magnetic Resonance
Author(s): Yusuke Nishiyama , Michal Malon , Yuji Ishii , Ayyalusamy Ramamoorthy
Homonuclear correlation NMR experiments are commonly used in the high-resolution structural studies of proteins. While 13C/13C chemical shift correlation experiments utilizing dipolar recoupling techniques are fully utilized under MAS, correlation of the chemical shifts of 15N nuclei in proteins has been a challenge. Previous studies have shown that the negligible 15N-15N dipolar coupling in peptides or proteins necessitates the use of a very long mixing time (typically several seconds) for effective spin diffusion to occur and considerably slows down a 15N/15N correlation experiment. In this study, we show that the use of mixing proton magnetization, instead of 15N, via the recoupled 1H-1H dipolar couplings enable faster 15N/15N correlation. In addition, the use of proton-detection under ultrafast MAS overcomes the sensitivity loss due to multiple magnetization transfer (between 1H and 15N nuclei) steps. In fact, less than 300 nL (~1.1 micromole quantity) sample is sufficient to acquire the 3D spectrum within 5 hours. Our results also demonstrate that a 3D 15N/15N/1H experiment can render higher resolution spectra that will be useful in the structural studies of proteins at ultrafast MAS frequencies. 3D 15N/15N/1H and 2D radio frequency-driven dipolar recoupling (RFDR)-based 1H/1H experimental results obtained from a powder sample of N-acetyla-L-15N-valyl-L-15N-leucine at 70 and 100 kHz MAS frequencies are presented. Graphical abstract
[NMR paper] Identifying inter-residue resonances in crowded 2D (13)C- (13)C chemical shift correlation spectra of membrane proteins by solid-state MAS NMR difference spectroscopy.
Identifying inter-residue resonances in crowded 2D (13)C- (13)C chemical shift correlation spectra of membrane proteins by solid-state MAS NMR difference spectroscopy.
Identifying inter-residue resonances in crowded 2D (13)C- (13)C chemical shift correlation spectra of membrane proteins by solid-state MAS NMR difference spectroscopy.
J Biomol NMR. 2013 May 25;
Authors: Miao Y, Cross TA, Fu R
Abstract
The feasibility of using difference spectroscopy, i.e. subtraction of two correlation spectra at different mixing times, for substantially...
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05-28-2013 06:36 PM
Identifying secondary structures in proteins using NMR chemical shift 3D correlation maps
Identifying secondary structures in proteins using NMR chemical shift 3D correlation maps
Available online 18 March 2013
Publication year: 2013
Source:Journal of Molecular Structure</br>
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NMR chemical shifts are accurate indicators of molecular environment and have been extensively used as aids in protein structure determination. This work focuses on creating empirical 3D correlation maps of backbone chemical shift nuclei for use as identifiers of secondary structure elements in proteins. A correlated database of backbone nuclei chemical shifts was constructed from...
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03-19-2013 12:58 AM
Solid state NMR of proteins at high MAS frequencies: symmetry-based mixing and simultaneous acquisition of chemical shift correlation spectra
Solid state NMR of proteins at high MAS frequencies: symmetry-based mixing and simultaneous acquisition of chemical shift correlation spectra
Abstract We have carried out chemical shift correlation experiments with symmetry-based mixing sequences at high MAS frequencies and examined different strategies to simultaneously acquire 3D correlation spectra that are commonly required in the structural studies of proteins. The potential of numerically optimised symmetry-based mixing sequences and the simultaneous recording of chemical shift correlation spectra such as: 3D NCAC and 3D NHH...
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11-29-2012 03:14 AM
[Question from NMRWiki Q&A forum] Pulse sequence for homonuclear correlation with SPC5 mixing period
Pulse sequence for homonuclear correlation with SPC5 mixing period
Hi,I'm looking for a pulse program suitable for Bruker Avance llI (topspin 2.1) which is 2D homonuclear correlation with a mixing period of the symmetry based pulse scheme - the SPC5 scheme. I took the basic PDSD experiment and just replaced the mixing period with the appropriate pulses of the SPC5 scheme but it didn't work. Does someone has a ready-to-run pulse scheme out there? Basically for 13C-13C correlation, the program starts with a 90 pulse on 1H, followed by CP from 1H to 13C, t1 evolution, 90 pulse on 13C, mixing...
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09-27-2012 03:49 PM
Chemical shift correlation at high MAS frequencies employing low-power symmetry-based mixing schemes
Chemical shift correlation at high MAS frequencies employing low-power symmetry-based mixing schemes
Abstract An approach for conveniently implementing low-power CN n ν and RN n ν symmetry-based band-selective mixing sequences for generating homo- and heteronuclear chemical shift correlation NMR spectra of low γ nuclei in biological solids is demonstrated. Efficient magnetisation transfer characteristics are achieved by selecting appropriate symmetries requiring the application of basic RF elements of relatively long duration and numerically tailoring the RF field modulation profile...
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06-20-2011 03:31 PM
31P NMR correlation maps of 18O/16O chemical shift isotopic effects for phosphometabolite labeling studies
31P NMR correlation maps of 18O/16O chemical shift isotopic effects for phosphometabolite labeling studies
Abstract Intramolecular correlations among the 18O-labels of metabolic oligophosphates, mapped by J-decoupled 31P NMR 2D chemical shift correlation spectroscopy, impart stringent constraints to the 18O-isotope distributions over the whole oligophosphate moiety. The multiple deduced correlations of isotopic labels enable determination of site-specific fractional isotope enrichments and unravel the isotopologue statistics. This approach ensures accurate determination of 18O-labeling...
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06-06-2011 12:53 AM
[NMR paper] CAMRA: chemical shift based computer aided protein NMR assignments.
CAMRA: chemical shift based computer aided protein NMR assignments.
Related Articles CAMRA: chemical shift based computer aided protein NMR assignments.
J Biomol NMR. 1998 Oct;12(3):395-405
Authors: Gronwald W, Willard L, Jellard T, Boyko RF, Rajarathnam K, Wishart DS, Sönnichsen FD, Sykes BD
A suite of programs called CAMRA (Computer Aided Magnetic Resonance Assignment) has been developed for computer assisted residue-specific assignments of proteins. CAMRA consists of three units: ORB, CAPTURE and PROCESS. ORB predicts NMR chemical shifts...
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11-17-2010 11:15 PM
Four-dimensional heteronuclear correlation experiments for chemical shift assignment of solid proteins
Four-dimensional heteronuclear correlation experiments for chemical shift assignment of solid proteins
W. Trent Franks, Kathryn D. Kloepper, Benjamin J. Wylie and Chad M. Rienstra
Journal of Biomolecular NMR; 2007; 39(2); pp 107 - 131
Abstract:
Chemical shift assignment is the first step in all established protocols for structure determination of uniformly labeled proteins by NMR. The explosive growth in recent years of magic-angle spinning (MAS) solid-state NMR (SSNMR) applications is largely attributable to improved methods for backbone and side-chain chemical shift correlation...