We have used 2H-nmr to study backbone dynamics of the 2H-labeled, slowly exchanging amide sites of fully hydrated, crystalline hen egg white lysozyme. Order parameters are determined from the residual quadrupole coupling and values increase from S2 = 0.85 at 290 K to S2 = 0.94 at 200 K. Dynamical rates are determined from spin-lattice relaxation at three nmr frequencies (38.8, 61.5, and 76.7 MHz). The approach used here is thus distinct from solution nmr studies where dynamical amplitudes and rates are both determined from relaxation measurements. At temperatures below 250 K, relaxation is independent of the nmr frequency indicating that backbone motions are fast compared to the nmr frequencies. However, as the temperature is increased above 250 K, relaxation is significantly more efficient at the lowest frequency, which shows, in addition, the presence of motions that are slow compared to the nmr frequencies. Using the values of S2 determined from the residual quadrupole coupling and a model-free relaxation formalism that allows for fast and slow internal motions, we conclude that these slow motions have correlation times in the range of 0.1 to 1.0 microsecond and are effectively frozen out at 250 K where fast motions of the amide planes with approximately 15 ps effective correlation times and 9 degrees rms amplitudes dominate relaxation. The fast internal motions increase slightly in amplitude as the temperature rises toward 290 K, but the correlation time, as is also observed in solution nmr studies of RNase H, is approximately constant. These findings are consistent with hypotheses of dynamic glass transitions in hydrated proteins arising from temperature-dependent damping of harmonic modes of motion above the transition point.
Low-field one-dimensional and direction-dependent relaxation imaging of bovine articular cartilage
Low-field one-dimensional and direction-dependent relaxation imaging of bovine articular cartilage
Publication year: 2011
Source: Journal of Magnetic Resonance, Available online 10 September 2011</br>
Erik*Rössler, Carlos*Mattea, Ayret*Mollova, Siegfried*Stapf</br>
The structure of articular cartilage is separated into three layers of differently oriented collagen fibers, which is accompanied by a gradient of increasing glycosaminoglycan (GAG) and decreasing water concentration from the top layer towards the bone interface. The combined effect of these structural variations results in...
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Recent Developments in (15)N NMR Relaxation Studies that Probe Protein Backbone Dynamics.
Recent Developments in (15)N NMR Relaxation Studies that Probe Protein Backbone Dynamics.
Recent Developments in (15)N NMR Relaxation Studies that Probe Protein Backbone Dynamics.
Top Curr Chem. 2011 Sep 7;
Authors: Ishima R
Abstract
Nuclear Magnetic Resonance (NMR) relaxation is a powerful technique that provides information about internal dynamics associated with configurational energetics in proteins, as well as site-specific information involved in conformational equilibria. In particular, (15)N relaxation is a useful probe to...
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09-08-2011 06:50 PM
Can Enzyme Engineering Benefit from the Modulation of Protein Motions? Lessons Learned from NMR Relaxation Dispersion Experiments.
Can Enzyme Engineering Benefit from the Modulation of Protein Motions? Lessons Learned from NMR Relaxation Dispersion Experiments.
Can Enzyme Engineering Benefit from the Modulation of Protein Motions? Lessons Learned from NMR Relaxation Dispersion Experiments.
Protein Pept Lett. 2011 Jan 11;
Authors:
Despite impressive progress in protein engineering and design, our ability to create new and efficient enzyme activities remains a laborious and time-consuming endeavor. In the past few years, intricate combinations of rational mutagenesis, directed...
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01-13-2011 12:00 PM
[NMR paper] Backbone dynamics of the olfactory marker protein as studied by 15N NMR relaxation measurements.
Backbone dynamics of the olfactory marker protein as studied by 15N NMR relaxation measurements.
Related Articles Backbone dynamics of the olfactory marker protein as studied by 15N NMR relaxation measurements.
Biochemistry. 2005 Jul 19;44(28):9673-9
Authors: Gitti RK, Wright NT, Margolis JW, Varney KM, Weber DJ, Margolis FL
Nuclear magnetic resonance (NMR) (15)N relaxation measurements of the olfactory marker protein (OMP) including longitudinal relaxation (T(1)), transverse relaxation (T(2)), and (15)N-{(1)H} NOE data were collected at low...
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12-01-2010 06:56 PM
[NMR paper] Site-specific backbone dynamics from a crystalline protein by solid-state NMR spectro
Site-specific backbone dynamics from a crystalline protein by solid-state NMR spectroscopy.
Related Articles Site-specific backbone dynamics from a crystalline protein by solid-state NMR spectroscopy.
J Am Chem Soc. 2004 Sep 22;126(37):11422-3
Authors: Giraud N, Böckmann A, Lesage A, Penin F, Blackledge M, Emsley L
Site-specific nitrogen-15 longitudinal relaxation rates are measured for the microcrystalline dimeric form of the protein Crh using multidimensional high-resolution solid-state NMR methods. The measured rates are used to provide a...
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11-24-2010 10:01 PM
[NMR paper] Backbone dynamics of the human MIA protein studied by (15)N NMR relaxation: implicati
Backbone dynamics of the human MIA protein studied by (15)N NMR relaxation: implications for extended interactions of SH3 domains.
Related Articles Backbone dynamics of the human MIA protein studied by (15)N NMR relaxation: implications for extended interactions of SH3 domains.
Protein Sci. 2003 Mar;12(3):510-9
Authors: Stoll R, Renner C, Buettner R, Voelter W, Bosserhoff AK, Holak TA
The melanoma inhibitory activity (MIA) protein is a clinically valuable marker in patients with malignant melanoma as enhanced values diagnose metastatic...
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11-24-2010 09:01 PM
[NMR paper] Internal motions of apo-neocarzinostatin as studied by 13C NMR methine relaxation at
Internal motions of apo-neocarzinostatin as studied by 13C NMR methine relaxation at natural abundance.
Related Articles Internal motions of apo-neocarzinostatin as studied by 13C NMR methine relaxation at natural abundance.
J Biomol NMR. 1995 Apr;5(3):233-44
Authors: Mispelter J, Lefèvre C, Adjadj E, Quiniou E, Favaudon V
Dynamics of the backbone and some side chains of apo-neocarzinostatin, a 10.7 kDa carrier protein, have been studied from 13C relaxation rates R1, R2 and steady-state 13C-(1H) NOEs, measured at natural abundance. Relaxation...
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08-22-2010 03:41 AM
[NMR paper] 15N NMR relaxation studies of the FK506 binding protein: backbone dynamics of the unc
15N NMR relaxation studies of the FK506 binding protein: backbone dynamics of the uncomplexed receptor.
Related Articles 15N NMR relaxation studies of the FK506 binding protein: backbone dynamics of the uncomplexed receptor.
Biochemistry. 1993 Sep 7;32(35):9000-10
Authors: Cheng JW, Lepre CA, Chambers SP, Fulghum JR, Thomson JA, Moore JM
Backbone dynamics of the major tacrolimus (FK506) binding protein (FKBP-12, 107 amino acids) have been studied using 15N relaxation data derived from proton-detected two-dimensional 1H-15N NMR spectroscopy....