Autor: |
Fiamingo FG; Department of Physics and Biophysics Program, University of Virginia, Charlottesville 22901., Brill AS, Hampton DA, Thorkildsen R |
Jazyk: |
angličtina |
Zdroj: |
Biophysical journal [Biophys J] 1989 Jan; Vol. 55 (1), pp. 67-77. |
DOI: |
10.1016/S0006-3495(89)82781-X |
Abstrakt: |
The orientation and temperature dependence (4.2-2.5 K) of electron paramagnetic resonance (EPR) power saturation and spin-lattice relaxation rate, and the orientation dependence of signal linewidth, were measured in single crystals of the aquo complex of ferric sperm whale skeletal muscle myoglobin. The spin-packet linewidth was found to be temperature independent and to vary by a factor of seven within the heme plane. An analysis is presented which enables one to arrive at (a) hyperfine component line-widths and, from the in-plane angular variation of the latter, at (b) the widths of distributions in energy differences between low-lying electronic levels and (c) the angular spread in the in-plane principal g-directions. The values of the energy level distributions in crystals obtained from the measurements and analysis reported here are compared with those obtained by a different method for the same protein complex in frozen solution. The spread in the rhombic energy splitting is significantly greater in solution than in the crystal. |
Databáze: |
MEDLINE |
Externí odkaz: |
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