Journal of Biomolecular NMR

, Volume 26, Issue 3, pp 249–257

Observation of a distinct transition in the mode of interconversion of ring pucker conformers in non-crystalline d-ribose-2′-d from 2H NMR spin-alignment

  • Andy C. LiWang
  • David E. McCready
  • Gary P. Drobny
  • Brian R. Reid
  • Michael A. Kennedy
Article

DOI: 10.1023/A:1023899100654

Cite this article as:
LiWang, A.C., McCready, D.E., Drobny, G.P. et al. J Biomol NMR (2003) 26: 249. doi:10.1023/A:1023899100654

Abstract

Internal motions of d-ribose selectively 2H-labeled at the 2 position were measured using solid state 2H NMR experiments. A sample of d-ribose-2-d was prepared in a hydrated, non-crystalline state to eliminate effects of crystal-packing. Between temperatures of −74 and −60 °C the C2–H2 bond was observed to undergo two kinds of motions which were similar to those of C2–H2/H2′′ found previously in crystalline deoxythymidine (Hiyama et al. (1989) J. Am. Chem. Soc., 111, 8609–8613): (1) Nanosecond motion of small angular displacement with an apparent activation energy of 3.6 ± 0.7 kcal mol−1, and (2) millisecond to microsecond motion of large amplitude with an apparent activation energy ≥4 kcal mol−1. At −74 °C, the slow, large-amplitude motion was best characterized as a two-site jump with a correlation time on the millisecond time scale, whereas at −60 °C it was diffusive on the microsecond time scale. The slow, large-amplitude motions of the C2–H2 bond are most likely from interconversions between C2-endo and C3-endo by way of the O4-endo conformation, whereas the fast, small-amplitude motions are probably librations of the C2–H2 bond within the C2-endo and C3-endo potential energy minima.

Arrhenius deuterium internal motions ribose solid state NMR spin alignment X-ray diffraction 

Copyright information

© Kluwer Academic Publishers 2003

Authors and Affiliations

  • Andy C. LiWang
    • 1
  • David E. McCready
    • 2
  • Gary P. Drobny
    • 3
  • Brian R. Reid
    • 3
  • Michael A. Kennedy
    • 4
  1. 1.Department of Biochemistry & BiophysicsTexas A&M UniversityCollege StationU.S.A.
  2. 2.Interfacial and Nano Science Facility, Pacific Northwest National Laboratory, EMSL 2569, K8-98RichlandU.S.A
  3. 3.Department of ChemistryUniversity of WashingtonSeattleU.S.A
  4. 4.Macromolecular Structure & Dynamics, Biological Sciences Laboratory, Pacific Northwest National Laboratory, EMSL 2569, K8-98RichlandU.S.A.

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