Comparison of fast backbone dynamics at amide nitrogen and carbonyl sites in dematin

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Abstract We perform a detailed comparison of fast backbone dynamics probed at amide nitrogen versus carbonyl carbon sites for dematin headpiece C-terminal domain (DHP) and its S74E mutant (DHPS74E). Carbonyl dynamics is probed via auto-correlated longitudinal rates and transverse Câ?²/Câ?²-Cα CSA/dipolar and Câ?²/Câ?²â??N CSA/dipolar cross-correlated rates, while 15N data are taken from a previous study. Resulting values of effective order parameters and internal correlation times support the conclusion that Câ?² relaxation reports on a different subset of fast motions compared to those probed at Nâ??H bond vectors in the same peptide planes. 13Câ?² order parameters are on the average 0.08 lower than 15N order parameters with the exception of the flexible loop region in DHP. The reduction of mobility in the loop region upon the S74E mutation can be seen from the 15N order parameters but not from the 13C order parameters. Internal correlation times at 13Câ?² sites are on the average an order of magnitude longer than those at 15N sites for the well-structured C-terminal subdomains, while the more flexible N-terminal subdomains have more comparable average internal correlation times.

• Content Type Journal Article
• DOI 10.1007/s10858-010-9417-9
• Authors
  • Liliya Vugmeyster, University of Alaska at Anchorage Department of Chemistry and Environment and Natural Resources Institute 3211 Providence Drive Anchorage AK 99508 USA
  • Dmitry Ostrovsky, University of Alaska at Anchorage Department of Mathematical Sciences 3211 Providence Drive Anchorage AK 99508 USA
  • Ying Li, Columbia University Department of Biochemistry & Molecular Biophysics 630 West 168th Street New York NY 10032 USA

• • Journal Journal of Biomolecular NMR
  • Online ISSN 1573-5001
  • Print ISSN 0925-2738
  • Journal Volume Volume 47
  • Journal Issue Volume 47, Number 2

Source: Journal of Biomolecular NMR