Motions of the backbone C alpha H alpha and threonine C beta H beta bonds of toxin alpha were investigated using natural abundance 13C NMR and molecular dynamics. Measurement of the 13C longitudinal and transverse relaxation rates employed ACCORDION techniques together with coherence selection by pulsed field gradients and sensitivity enhancement through the use of preservation of equivalent pathway, thus allowing a considerable reduction of the required spectrometer time. 13C R1, R2, 1H-->13C NOE were obtained, as well as the variations of R1 rho (90 degrees) as a function of the rf field strength. These data were compared to those recorded by 1H and 15N NMR on a labelled sample of the toxin [Guenneugues et al. (1997) Biochemistry, 36, 16097-16108]. Both sets of data showed that picosecond to nanosecond time scale motions are well correlated to the secondary structure of the protein. This was further reinforced by the analysis of a 1 ns molecular dynamics simulation in water. Several C alpha H alpha and threonine C beta H beta experimentally exhibit fast motions with a correlation time longer than 500 ps, that cannot be sampled along the simulation. In addition, the backbone exhibits motions on the microsecond to millisecond time scale on more than half of its length. Thus, toxin alpha, a highly stable protein (Tm = 75 degrees C at acidic pH) containing 61 amino acids and 4 disulfides, shows important internal motions on time scales ranging from 0.1-0.5 ps, to 10-100 ps, 1 ns, and about 30 microseconds to 10 ms.
[NMR paper] NMR solution structure of a highly stable de novo heterodimeric coiled-coil.
NMR solution structure of a highly stable de novo heterodimeric coiled-coil.
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Biopolymers. 2004 Dec 5;75(5):367-75
Authors: Lindhout DA, Litowski JR, Mercier P, Hodges RS, Sykes BD
The NMR solution structure of a highly stable coiled-coil IAAL-E3/K3 has been solved. The E3/K3 coiled-coil is a 42-residue de novo designed coiled-coil comprising three heptad repeats per subunit, stabilized by hydrophobic contacts within the core and electrostatic...
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[NMR paper] How to detect internal motion by homonuclear NMR.
How to detect internal motion by homonuclear NMR.
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J Am Chem Soc. 2002 May 22;124(20):5881-9
Authors: Schleucher J, Wijmenga SS
NOESY and ROESY cross-peak intensities depend on internuclear distances and internal motion. Internal motion is usually ignored, and NOESY cross-peak intensities are interpreted in terms of internuclear distances only. Off-resonance ROESY experiments measure a weighted average of NOE and ROE. The weight can be described and experimentally set by an...
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[NMR paper] Relaxation of water protons in highly concentrated aqueous protein systems studied by
Relaxation of water protons in highly concentrated aqueous protein systems studied by 1H NMR spectroscopy.
Related Articles Relaxation of water protons in highly concentrated aqueous protein systems studied by 1H NMR spectroscopy.
Z Naturforsch C. 2001 Nov-Dec;56(11-12):1075-81
Authors: Szuminska K, Gutsze A, Kowalczyk A
Concentrated Aqueous Protein Systems, Proton Relaxation Times, Slow Chemical Exchange In this paper we present proton spin-lattice (T1) and spin-spin (T2) relaxation times measured vs. concentration, temperature, pulse...
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[NMR paper] Mutational analysis and NMR spectroscopy of quail cysteine and glycine-rich protein C
Mutational analysis and NMR spectroscopy of quail cysteine and glycine-rich protein CRP2 reveal an intrinsic segmental flexibility of LIM domains.
Related Articles Mutational analysis and NMR spectroscopy of quail cysteine and glycine-rich protein CRP2 reveal an intrinsic segmental flexibility of LIM domains.
J Mol Biol. 1999 Oct 1;292(4):893-908
Authors: Kloiber K, Weiskirchen R, Kräutler B, Bister K, Konrat R
The LIM domain is a conserved cysteine and histidine-containing structural module of two tandemly arranged zinc fingers. It has been...
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[NMR paper] Dynamic NMR spectral analysis and protein folding: identification of a highly populat
Dynamic NMR spectral analysis and protein folding: identification of a highly populated folding intermediate of rat intestinal fatty acid-binding protein by 19F NMR.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www.pubmedcentral.nih.gov-corehtml-pmc-pmcgifs-pubmed-pmc.gif Related Articles Dynamic NMR spectral analysis and protein folding: identification of a highly populated folding intermediate of rat intestinal fatty acid-binding protein by 19F NMR.
Proc Natl Acad Sci U S A. 1992 Aug 1;89(15):7222-6
Authors: Ropson IJ, Frieden C
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[NMR paper] Engineering out motion: a surface disulfide bond alters the mobility of tryptophan 22
Engineering out motion: a surface disulfide bond alters the mobility of tryptophan 22 in cytochrome b5 as probed by time-resolved fluorescence and 1H NMR experiments.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--pubs.acs.org-images-acspubs.jpg Related Articles Engineering out motion: a surface disulfide bond alters the mobility of tryptophan 22 in cytochrome b5 as probed by time-resolved fluorescence and 1H NMR experiments.
Biochemistry. 1999 Apr 20;38(16):5065-75
Authors: Storch EM, Grinstead JS, Campbell AP, Daggett V, Atkins WM
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Internal motion time scales of a small, highly stable and disulfide-rich protein: a 1
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