Related ArticlesAssessing potential bias in the determination of rotational correlation times of proteins by NMR relaxation.
J Biomol NMR. 1999 Feb;13(2):101-12
Authors: Lee AL, Wand AJ
The various factors that influence the reliable and efficient determination of the correlation time describing molecular reorientation of proteins by NMR relaxation methods are examined. Nuclear Overhauser effects, spin-lattice, and spin-spin relaxation parameters of 15N NMR relaxation in ubiquitin have been determined at 17.6, 14.1, 11.7 and 9.4 Tesla. This unusually broad set of relaxation parameters has allowed the examination of the influence of chemical shift anisotropy, the functional form of the model-free spectral density, and the reliability of determined spin-spin relaxation parameters on the characterization of global tumbling of the protein. Treating the 15N chemical shift anisotropy (CSA) as an adjustable parameter, a consensus value of -170 +/- 15 ppm for the breadth of the chemical shift tensor and a global isotropic correlation time of 4.1 ns are found when using the model-free spectral density to fit T1 and NOE data from all fields. The inclusion of T2 relaxation parameters in the determination of the global correlation time results in its increase to 4.6 ns. This apparent inconsistency may explain a large portion of the discrepancy often found between NMR- and fluorescence-derived tau m values for proteins. The near identity of observed T2 and T1 rho values suggests that contributions from slow motions are not the origin of the apparent inconsistency with obtained T1 and NOE data. Various considerations suggest that the origin of this apparent discrepancy may reside in a contribution to the spectral density at zero frequency that is not represented by the simple model-free formalism in addition to the usual experimental difficulties associated with the measurement of these relaxation parameters. Finally, an axially symmetric diffusion tensor for ubiquitin is obtained using exclusively T1 and NOE data. A recommendation is reached on the types and combinations of relaxation data that can be used to reliably determine tau m values. It is also noted that the reliable determination of tau m values from 15N T1 and NOE relaxation parameters will become increasingly difficult as tau m increases.
[NMR paper] Effective rotational correlation times of proteins from NMR relaxation interference.
Effective rotational correlation times of proteins from NMR relaxation interference.
Related Articles Effective rotational correlation times of proteins from NMR relaxation interference.
J Magn Reson. 2006 Jan;178(1):72-6
Authors: Lee D, Hilty C, Wider G, Wüthrich K
Knowledge of the effective rotational correlation times, tauc, for the modulation of anisotropic spin-spin interactions in macromolecules subject to Brownian motion in solution is of key interest for the practice of NMR spectroscopy in structural biology. The value of tauc enables...
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[NMR paper] In vivo 13C NMR metabolite profiling: potential for understanding and assessing conifer seed quality.
In vivo 13C NMR metabolite profiling: potential for understanding and assessing conifer seed quality.
Related Articles In vivo 13C NMR metabolite profiling: potential for understanding and assessing conifer seed quality.
J Exp Bot. 2005 Aug;56(418):2253-65
Authors: Terskikh VV, Feurtado JA, Borchardt S, Giblin M, Abrams SR, Kermode AR
High-resolution 13C MAS NMR spectroscopy was used to profile a range of primary and secondary metabolites in vivo in intact whole seeds of eight different conifer species native to North America, including six of...
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[NMR paper] Determination of protein rotational correlation time from NMR relaxation data at vari
Determination of protein rotational correlation time from NMR relaxation data at various solvent viscosities.
Related Articles Determination of protein rotational correlation time from NMR relaxation data at various solvent viscosities.
J Biomol NMR. 2004 Dec;30(4):431-42
Authors: Korchuganov DS, Gagnidze IE, Tkach EN, Schulga AA, Kirpichnikov MP, Arseniev AS
An accurate determination of the overall rotation of a protein plays a crucial role in the investigation of its internal motions by NMR. In the present work, an innovative approach to the...
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[NMR paper] Potential bias in NMR relaxation data introduced by peak intensity analysis and curve
Potential bias in NMR relaxation data introduced by peak intensity analysis and curve fitting methods.
Related Articles Potential bias in NMR relaxation data introduced by peak intensity analysis and curve fitting methods.
J Biomol NMR. 2001 Sep;21(1):1-9
Authors: Viles JH, Duggan BM, Zaborowski E, Schwarzinger S, Huntley JJ, Kroon GJ, Dyson HJ, Wright PE
We present an evaluation of the accuracy and precision of relaxation rates calculated using a variety of methods, applied to data sets obtained for several very different protein systems. We...
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[NMR paper] Some NMR experiments and a structure determination employing a [15N,2H] enriched prot
Some NMR experiments and a structure determination employing a enriched protein.
Related Articles Some NMR experiments and a structure determination employing a enriched protein.
J Biomol NMR. 1998 Aug;12(2):259-76
Authors: Mal TK, Matthews SJ, Kovacs H, Campbell ID, Boyd J
We present the results of studies of an aqueous sample of a highly enriched protein, the SH3 domain from Fyn. Measurements of 1H relaxation and interactions between H2O solvent and exchangeable protons are given, as well as a method for increasing the effective...
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[NMR paper] Determination of helix-helix interactions in membranes by rotational resonance NMR.
Determination of helix-helix interactions in membranes by rotational resonance NMR.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www.pubmedcentral.nih.gov-corehtml-pmc-pmcgifs-pubmed-pmc.gif Related Articles Determination of helix-helix interactions in membranes by rotational resonance NMR.
Proc Natl Acad Sci U S A. 1995 Jan 17;92(2):488-91
Authors: Smith SO, Bormann BJ
Dimerization of human glycophorin A in erythrocyte membranes is mediated by specific interactions within the helical transmembrane domain of the protein. Rotational...
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[NMR paper] Determination of membrane protein structure by rotational resonance NMR: bacteriorhod
Determination of membrane protein structure by rotational resonance NMR: bacteriorhodopsin.
Related Articles Determination of membrane protein structure by rotational resonance NMR: bacteriorhodopsin.
Science. 1991 Feb 15;251(4995):783-6
Authors: Creuzet F, McDermott A, Gebhard R, van der Hoef K, Spijker-Assink MB, Herzfeld J, Lugtenburg J, Levitt MH, Griffin RG
Rotationally resonant magnetization exchange, a new nuclear magnetic resonance (NMR) technique for measuring internuclear distances between like spins in solids, was used to determine...
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HIFI-NMR: 10 times faster than regular NMR
High-Resolution Iterative Frequency Identification for NMR as a General Strategy for Multidimensional Data Collection
Hamid R. Eghbalnia, Arash Bahrami, Marco Tonelli, Klaas Hallenga, and John L. Markley
J. Am. Chem. Soc.; 2005; 127(36) pp 12528 - 12536
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Abstract:
We describe a novel approach to the rapid collection and processing of multidimensional NMR data: "high-resolution iterative frequency identification for NMR" (HIFI-NMR). As with other reduced dimensionality approaches, HIFI-NMR collects...