Backbone dynamics of the olfactory marker protein as studied by 15N NMR relaxation measurements

Biochemistry. 2005 Jul 19;44(28):9673-9. doi: 10.1021/bi050149t.

Abstract

Nuclear magnetic resonance (NMR) (15)N relaxation measurements of the olfactory marker protein (OMP) including longitudinal relaxation (T(1)), transverse relaxation (T(2)), and (15)N-{(1)H} NOE data were collected at low protein concentrations (<or=100 microM) and at two field strengths (14.4 and 18.8 T) for 135 of 162 backbone amide groups. Rotational diffusion of the OMP was found to be axially symmetric with D( parallel)/D( perpendicular) = 1.20 +/- 0.02 with an overall global correlation time of 8.93 +/- 0.03 ns. Model-free internal dynamic analyses of these data provided a description of the protein's dynamics on multiple time scales. The results of these studies indicate that there is a large degree of conformational flexibility for alpha-helix 1 (alpha1), loop 1, and the conserved Omega-loop (loop 3). The functional significance that these dynamic regions of OMP have in modulating olfactory signal transduction is discussed.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Anisotropy
  • Models, Molecular
  • Nerve Tissue Proteins / chemistry*
  • Nerve Tissue Proteins / physiology
  • Nitrogen Isotopes
  • Nuclear Magnetic Resonance, Biomolecular / methods
  • Olfactory Marker Protein
  • Protein Conformation
  • Protein Structure, Secondary
  • Rats
  • Signal Transduction / physiology
  • Solutions
  • Thermodynamics*

Substances

  • Nerve Tissue Proteins
  • Nitrogen Isotopes
  • Olfactory Marker Protein
  • Omp protein, rat
  • Solutions