Correlated motions of C'-N and C α-C β pairs in protonated and per-deuterated GB3

J Biomol NMR. 2018 Oct;72(1-2):39-54. doi: 10.1007/s10858-018-0205-2. Epub 2018 Aug 18.

Abstract

We investigated correlated µs-ms time scale motions of neighboring 13C'-15N and 13Cα-13Cβ nuclei in both protonated and perdeuterated samples of GB3. The techniques employed, NMR relaxation due to cross-correlated chemical shift modulations, specifically target concerted changes in the isotropic chemical shifts of the two nuclei associated with spatial fluctuations. Field-dependence of the relaxation rates permits identification of the parameters defining the chemical exchange rate constant under the assumption of a two-site exchange. The time scale of motions falls into the intermediate to fast regime (with respect to the chemical shift time scale, 100-400 s-1 range) for the 13C'-15N pairs and into the slow to intermediate regime for the 13Cα-13Cβ pairs (about 150 s-1). Comparison of the results obtained for protonated and deuterated GB3 suggests that deuteration has a tendency to reduce these slow scale correlated motions, especially for the 13Cα-13Cβ pairs.

Keywords: Correlated motions; Cross-correlation NMR relaxation; Deuteration; GB3; Protein dynamics.

MeSH terms

  • Antigens, Tumor-Associated, Carbohydrate / chemistry*
  • Carbon Isotopes
  • Chemistry Techniques, Analytical
  • Deuterium
  • Molecular Dynamics Simulation
  • Motion*
  • Nitrogen Isotopes
  • Nuclear Magnetic Resonance, Biomolecular / methods*

Substances

  • Antigens, Tumor-Associated, Carbohydrate
  • Carbon Isotopes
  • Gb3 antigen
  • Nitrogen Isotopes
  • Nitrogen-15
  • Deuterium
  • Carbon-13