[Transition between iron spin states in myoglobin: Roentgen absorption].
The spin transition of Fe in the active center of a myoglobin molecule, stimulated by a temperature variation, was studied by the theoretical multiple scattering analysis of experimental X-ray absorption data. The spin transition was followed by the movement of the Fe ion out of the plane of the heme without substantial changes in the Fe-N distance. It was shown that the X-ray absorption fine structure above the Fe K-edge is sensitive to both local geometry changes near the Fe ion in the active site of the protein and the spin state of the Fe ion itself. The change in the symmetry of Fe coordination lead to modifications of the spectrum shape in the entire interval up to 40 eV above the main edge. It was found that the spin state effects mostly the rising edge, and at energies above 15 eV becomes negligibly small.
Soldatov
A V
AV
Department of Physics, Rostov State University, B. Sadovaya 105, Rostov-na-Donu, 344006 Russia.
Ialovega
G E
GE
Smolentsev
G Iu
GIu
Kovtun
A P
AP
Della Longa
S
S
D007501:Iron / Q000737:chemistry*; D008024:Ligands; D015394:Molecular Structure; D009211:Myoglobin / Q000737:chemistry*; D011789:Quantum Theory; D013052:Spectrometry, X-Ray Emission; D013696:Temperature
D008024:Ligands; D009211:Myoglobin; D007501:Iron