Related ArticlesNMR determination of the orientation of the magnetic susceptibility tensor in cyanometmyoglobin: a new probe of steric tilt of bound ligand.
Biochemistry. 1990 Feb 13;29(6):1556-66
Authors: Emerson SD, La Mar GN
The experimentally determined paramagnetic dipolar shifts for noncoordinated amino acid side-chain protons in the heme pocket of sperm whale cyanometmyoglobin [Emerson, S. d., & La Mar, G. N. (1990) Biochemistry (preceding paper in this issue]) were used to determine in solution the orientation of the principal axes for the paramagnetic susceptibility tensor relative to the heme iron molecular coordinates. The determination was made by a least-squares search for the unique Euler rotation angles which convert the geometric factors in the molecular (crystal) coordinates to ones that correctly predict each of 41 known dipolar shifts by using the magnetic anisotropies computed previously [Horrocks, W. D., Jr., & Greenberg, E. S. (973) Biochim. Biophys. Acta 322, 38-44]. An excellent fit to experimental shifts was obtained, which also provided predictions that allowed subsequent new assignments to be made. The magnetic axes are oriented so that the z axis is tipped approximately 15 degrees from the heme normal toward the hem delta-meso-H and coincides approximately with the characterized FeCO tilt axis in the isostructural MbCO complex [Kuriyan, J., Wilz, S., Karplus, M., & Petsko, G. A. (1986) J. Mol. Biol. 192, 133-154]. Since the FeCO and FeCN units are isostructural, we propose that the dominant protein constraints that tips the magnetic z axis from the heme normal is the tilt of the FeCN by steric interactions with the distal residues. The rhombic magnetic axes were found to align closely with the projection of the proximal His imidazole plane on the heme, confirming that the His-Fe bonding provides the protein constraints that orients the in-plane anisotrophy. The tipped magnetic z axis is shown to account quantitatively for the previously noted major discrepancy between the hyperfine shift patterns for the bound imidazole side chain in models and protein. Moreover, it is shown that the proximal His ring nolabile proton hyperfine shifts provide direct and exquisitely sensitive indicators of the degree of the z axis tilt that may serve as a valuable probe for characterizing variable steric interactions in the distal pocket of both point mutants and natural genetic variants of myoglobin.
Construction and performance of an NMR tube with a sample cavity formed within magnetic susceptibility-matched glass.
Construction and performance of an NMR tube with a sample cavity formed within magnetic susceptibility-matched glass.
Construction and performance of an NMR tube with a sample cavity formed within magnetic susceptibility-matched glass.
J Magn Reson. 2011 Apr;209(2):167-73
Authors: Takeda M, Hallenga K, Shigezane M, Waelchli M, Löhr F, Markley JL, Kainosho M
We describe the construction and performance of an NMR tube with a magnetic susceptibility matched sample cavity that confines the solution within the detection zone in the axial direction and...
Impact of (15)N R(2)/R(1) Relaxation Restraints on Molecular Size, Shape, and Bond Vector Orientation for NMR Protein Structure Determination with Sparse Distance Restraints.
Impact of (15)N R(2)/R(1) Relaxation Restraints on Molecular Size, Shape, and Bond Vector Orientation for NMR Protein Structure Determination with Sparse Distance Restraints.
Impact of (15)N R(2)/R(1) Relaxation Restraints on Molecular Size, Shape, and Bond Vector Orientation for NMR Protein Structure Determination with Sparse Distance Restraints.
J Am Chem Soc. 2011 Apr 4;
Authors: Ryabov Y, Schwieters CD, Clore GM
(15)N R(2)/R(1) relaxation data contain information on molecular shape and size as well as on bond vector orientations relative to...
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Impact of 15N R2/R1 Relaxation Restraints on Molecular Size, Shape, and Bond Vector Orientation for NMR Protein Structure Determination with Sparse Distance Restraints
Impact of 15N R2/R1 Relaxation Restraints on Molecular Size, Shape, and Bond Vector Orientation for NMR Protein Structure Determination with Sparse Distance Restraints
Yaroslav Ryabov, Charles D. Schwieters and G. Marius Clore
http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/0/jacsat.ahead-of-print/ja201020c/aop/images/medium/ja-2011-01020c_0002.gif
Journal of the American Chemical Society
DOI: 10.1021/ja201020c
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http://feeds.feedburner.com/~r/acs/jacsat/~4/3J1IyCLkQMQ
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[NMR paper] Magnetic susceptibility tensor and heme contact shifts determinations in the Rhodobac
Magnetic susceptibility tensor and heme contact shifts determinations in the Rhodobacter capsulatus ferricytochrome c': NMR and magnetic susceptibility studies.
Related Articles Magnetic susceptibility tensor and heme contact shifts determinations in the Rhodobacter capsulatus ferricytochrome c': NMR and magnetic susceptibility studies.
J Am Chem Soc. 2001 Mar 14;123(10):2231-42
Authors: Tsan P, Caffrey M, Daku ML, Cusanovich M, Marion D, Gans P
The 1H and 15N resonances of the carbon monoxide complex of ferrocytochrome c' of Rhodobacter...
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[NMR paper] Direct determination of changes of interdomain orientation on ligation: use of the or
Direct determination of changes of interdomain orientation on ligation: use of the orientational dependence of 15N NMR relaxation in Abl SH(32).
Related Articles Direct determination of changes of interdomain orientation on ligation: use of the orientational dependence of 15N NMR relaxation in Abl SH(32).
Biochemistry. 1999 Aug 10;38(32):10225-30
Authors: Fushman D, Xu R, Cowburn D
The relative orientation and motions of domains within many proteins are key to the control of multivalent recognition, or the assembly of protein-based cellular...
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Determination of relative tensor orientations by ?-encoded chemical shift anisotropy/
Determination of relative tensor orientations by ?-encoded chemical shift anisotropy/heteronuclear dipolar coupling 3D NMR spectroscopy in biological solids.
Related Articles Determination of relative tensor orientations by ?-encoded chemical shift anisotropy/heteronuclear dipolar coupling 3D NMR spectroscopy in biological solids.
Phys Chem Chem Phys. 2010 Oct 8;
Authors: Hou G, Paramasivam S, Byeon IJ, Gronenborn AM, Polenova T
In this paper, we present 3D chemical shift anisotropy (CSA)/dipolar coupling correlation experiments, based on ?-encoded...