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Author Spotlight: Exploring Intrinsically Disordered Protein Dynamics Through NMR Relaxation Experiments
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Author Spotlight: Exploring Intrinsically Disordered Protein Dynamics Through NMR Relaxation Experiments

Published on: November 1, 2024

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Slow motions in microcrystalline proteins as observed by MAS-dependent 15N rotating-frame NMR relaxation

Alexey Krushelnitsky1, Tatiana Zinkevich1, Bernd Reif2

  • 1Institut für Physik, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str.7, D-06120 Halle, Germany.

Journal of Magnetic Resonance (San Diego, Calif. : 1997)
|October 6, 2014
PubMed

Insights

(15)N NMR relaxation rate R1ρ measurements show significant protein dynamics in the microcrystalline chicken alpha-spectrin SH3 domain. Proton-diluted samples and moderate MAS rates are advantageous for quantifying slow molecular mobility.

Area of Science:

  • Biochemistry
  • Structural Biology
  • Nuclear Magnetic Resonance (NMR) Spectroscopy

Background:

  • Protein dynamics are crucial for function.
  • The alpha-spectrin SH3 domain is a key protein module.
  • Understanding protein dynamics requires advanced NMR techniques.

Purpose of the Study:

  • To investigate the dynamics of the chicken alpha-spectrin SH3 domain.
  • To quantify slow dynamics (μs-ms) using (15)N NMR relaxation.
  • To optimize experimental conditions for studying slow protein motions.

Main Methods:

  • (15)N NMR relaxation rate R1ρ measurements.
  • Comparison of 2D site-resolved and 1D integrated (15)N spectral intensities.
  • Experiments on proton-diluted protein samples.
  • Variable sample conditions including magic angle spinning (MAS) rates.

Main Results:

  • A substantial fraction of residues in the alpha-spectrin SH3 domain exhibit μs-ms dynamics.
  • Broad signals in 2D spectra correlate with pronounced slow mobility.
  • (15)N R1ρ measurements in proton-diluted samples are quantitatively reliable, free from spin-spin contributions.
  • Moderate MAS rates (10-30 kHz) are more effective than high rates (>50-60 kHz) for identifying slow dynamics.

Conclusions:

  • The chicken alpha-spectrin SH3 domain possesses significant slow dynamics.
  • (15)N R1ρ relaxation is a powerful tool for characterizing μs-ms motions.
  • Proton dilution and moderate MAS rates enhance the quantitative analysis of slow dynamics.
Keywords:
DynamicsMagic angle spinningRelaxationSH3 domainSolid-state

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