Non-uniform sampling has been successfully used for solution and solid-state NMR of homogeneous samples. In the solid state, protein samples are often dominated by inhomogeneous contributions to the homogeneous line widths. In spite of different technical strategies for peak reconstruction by different methods, we validate that NUS can generally be used also for such situations where spectra are made up of complex peak shapes rather than Lorentian lines. Using the RMSD between subsampled and reconstructed data and those spectra obtained with uniform sampling for a sample comprising a wide conformational distribution, we quantitatively evaluate the identity of inhomogeneous peak patterns. The evaluation comprises Iterative Soft Thresholding (hmsIST implementation) as a method explicitly not assuming Lorentian lineshapes, as well as Sparse Multidimensional Iterative Lineshape Enhanced (SMILE) algorithm and Signal Separation Algorithm (SSA) reconstruction, which do work on the basis of Lorentian lineshape models, with different sampling densities. Even though individual peculiarities are apparent, all methods turn out principally viable to reconstruct the heterogeneously broadened peak shapes.
[U. of Ottawa NMR Facility Blog] Decoupling Bandwidth and Distorted Line Shapes
Decoupling Bandwidth and Distorted Line Shapes
Broadband X nucleus decoupling (X = 13C, 15N, 31P, 11B, 19F etc.....) is frequently used in 1H detected 2D HSQC/HMQC data collection or in standard 1D 1H spectra to aid in structure assignment. When broadband decoupling schemes are used, one must keep in mind that they are not infinitely broadbanded. They have finite bandwidths over which they are effective thus limiting the chemical shift range for the decoupled nuclide. The effective bandwidth depends on the particular decoupling scheme and the decoupling power used. If multiple peaks...
[U. of Ottawa NMR Facility Blog] Non-uniform Sampling (NUS)
Non-uniform Sampling (NUS)
Collecting 2D or 3D NMR data can be very time consuming. The indirect dimension of a 2D experiment is sampled linearly via the t1 increments in the pulse sequence. An FID must be collected for every single linearly spaced t1 increment. In the interest in collecting 2D or 3D NMR data in a more time efficient manner, a great deal of effort is made towards faster data collection techniques. While some of these methods are based on spatial selectivity, others are based on sparse sampling techniques in the indirect dimensions of nD NMR sequences. One such sparse...
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05-11-2016 08:04 PM
[NMR paper] Non-uniform sampling of NMR relaxation data.
Non-uniform sampling of NMR relaxation data.
Related Articles Non-uniform sampling of NMR relaxation data.
J Biomol NMR. 2016 Feb 4;
Authors: Linnet TE, Teilum K
Abstract
The use of non-uniform sampling of NMR spectra may give significant reductions in the data acquisition time. For quantitative experiments such as the measurement of spin relaxation rates, non-uniform sampling is however not widely used as inaccuracies in peak intensities may lead to errors in the extracted dynamic parameters. By systematic reducing the coverage...
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02-06-2016 03:10 PM
Non-uniform sampling of NMR relaxation data
Non-uniform sampling of NMR relaxation data
Abstract
The use of non-uniform sampling of NMR spectra may give significant reductions in the data acquisition time. For quantitative experiments such as the measurement of spin relaxation rates, non-uniform sampling is however not widely used as inaccuracies in peak intensities may lead to errors in the extracted dynamic parameters. By systematic reducing the coverage of the Nyquist grid of 15N Carr-Purcell-Meiboom-Gill (CPMG) relaxation dispersion datasets for four different proteins and performing a full...
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02-05-2016 02:38 PM
[NMR paper] Time-resolved multidimensional NMR with non-uniform sampling.
Time-resolved multidimensional NMR with non-uniform sampling.
Time-resolved multidimensional NMR with non-uniform sampling.
J Biomol NMR. 2014 Jan 17;
Authors: Mayzel M, Rosenlöw J, Isaksson L, Orekhov VY
Abstract
Time-resolved experiments demand high resolution both in spectral dimensions and in time of the studied kinetic process. The latter requirement traditionally prohibits applications of the multidimensional experiments, which, although capable of providing invaluable information about structure and dynamics and almost unlimited...
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01-18-2014 11:31 AM
[NMR analysis blog] Non Uniform Sampling (NUS) NMR Processing
Non Uniform Sampling (NUS) NMR Processing
Background
In the last few years, Non-Uniform Sampling (NUS) has emerged as a very powerful tool to significantly speed up the acquisition of multidimensional NMR experiments due to the fact that only a subset of the usual linearly sampled data in the Nyquist grid is measured.
Unfortunately, this fast acquisition modality introduces a new challenge as the normal Fourier Transform will fail and consequently, special processing techniques are required.
A number of sophisticated methods have been proposed for reconstructing sparsely sampled 2D...
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12-21-2013 03:15 PM
NMR line shapes and multi-state binding equilibria
NMR line shapes and multi-state binding equilibria
Abstract Biological function of proteins relies on conformational transitions and binding of specific ligands. Proteinâ??ligand interactions are thermodynamically and kinetically coupled to conformational changes in protein structures as conceptualized by the models of pre-existing equilibria and induced fit. NMR spectroscopy is particularly sensitive to complex ligand-binding modesâ??NMR line-shape analysis can provide for thermodynamic and kinetic constants of ligand-binding equilibria with the site-specific resolution. However,...
Non-uniform sampling in quantitative assessment of heterogeneous solid-state NMR line shapes
Linear Mode
