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Assignment of paramagnetic 15N-HSQC spectra by heteronuclear exchange spectroscopy

Journal Article


Abstract


  • Paramagnetic metal ions in proteins provide a rich source of structural information, but the resonance assignments required to extract the information can be challenging. Here we demonstrate that paramagnetically shifted N-15-HSQC cross-peaks can be assigned using N-Z-exchange spectroscopy under conditions in which the paramagnetic form of the protein is in dynamic equilibrium with its diamagnetic form. Even slow exchange of specifically bound metal ions may be detected within the long lifetime of N-15 longitudinal magnetization of large proteins at high magnetic fields. Alternatively, the exchange can be accelerated using an excess of metal ions. In the resulting exchange spectra, paramagnetic N-15 resonances become visible for residues that are not directly observed in a conventional N-15-HSQC spectrum due to paramagnetic H-1(N) broadening. The experiments are illustrated by the 30 kDa lanthanide-binding epsilon 186/theta complex of DNA polymerase III in the presence of sub-stoichiometric amounts of Dy3+ or a mixture of Dy3+ and La3+.

Authors


  •   John, Michael (external author)
  •   Headlam, M.J. (external author)
  •   Dixon, Nicholas E.
  •   Otting, Gottfried (external author)

Publication Date


  • 2007

Citation


  • John, M., Headlam, M. J., Dixon, N. E. & Otting, G. (2007). Assignment of paramagnetic 15N-HSQC spectra by heteronuclear exchange spectroscopy. Journal of Biomolecular N M R, 37 (1), 43-51.

Scopus Eid


  • 2-s2.0-33845928943

Ro Metadata Url


  • http://ro.uow.edu.au/smhpapers/452

Has Global Citation Frequency


Number Of Pages


  • 8

Start Page


  • 43

End Page


  • 51

Volume


  • 37

Issue


  • 1

Place Of Publication


  • Netherlands

Abstract


  • Paramagnetic metal ions in proteins provide a rich source of structural information, but the resonance assignments required to extract the information can be challenging. Here we demonstrate that paramagnetically shifted N-15-HSQC cross-peaks can be assigned using N-Z-exchange spectroscopy under conditions in which the paramagnetic form of the protein is in dynamic equilibrium with its diamagnetic form. Even slow exchange of specifically bound metal ions may be detected within the long lifetime of N-15 longitudinal magnetization of large proteins at high magnetic fields. Alternatively, the exchange can be accelerated using an excess of metal ions. In the resulting exchange spectra, paramagnetic N-15 resonances become visible for residues that are not directly observed in a conventional N-15-HSQC spectrum due to paramagnetic H-1(N) broadening. The experiments are illustrated by the 30 kDa lanthanide-binding epsilon 186/theta complex of DNA polymerase III in the presence of sub-stoichiometric amounts of Dy3+ or a mixture of Dy3+ and La3+.

Authors


  •   John, Michael (external author)
  •   Headlam, M.J. (external author)
  •   Dixon, Nicholas E.
  •   Otting, Gottfried (external author)

Publication Date


  • 2007

Citation


  • John, M., Headlam, M. J., Dixon, N. E. & Otting, G. (2007). Assignment of paramagnetic 15N-HSQC spectra by heteronuclear exchange spectroscopy. Journal of Biomolecular N M R, 37 (1), 43-51.

Scopus Eid


  • 2-s2.0-33845928943

Ro Metadata Url


  • http://ro.uow.edu.au/smhpapers/452

Has Global Citation Frequency


Number Of Pages


  • 8

Start Page


  • 43

End Page


  • 51

Volume


  • 37

Issue


  • 1

Place Of Publication


  • Netherlands