J. Phys. Colloques
Volume 47, Numéro C8, Décembre 1986EXAFS and Near Edge Structure IV
|Page(s)||C8-1147 - C8-1150|
J. Phys. Colloques 47 (1986) C8-1147-C8-1150
HIGH-RESOLUTION XANES STUDY OF THERMAL SPIN EQUILIBRIUM IN MYOGLOBINH. OYANAGI1, E.W. SVASTITS2, T. IIZUKA3, T. MATSUSHITA4, S. SAIGO5, R. MAKINO3 et Y. ISHIMURA3
1 Electrotechnical Laboratory, Sakuramura, Niiharigun, Ibaraki 305, Japan
2 Department of Chemistry, University of South Carolina, Columbia, SC 29208, U.S.A.
3 Department of Biochemistry, School of Medicine, Keio University, Shinanomachi, Shinjuku, Tokyo 160, Japan
4 National Laboratory for High Energy Physics, Ohomachi, Tsukubagun, Ibaraki 305, Japan
5 Department of Physics, Jichi Medical School, Yakushiji, Minamikawachi, Tochigi 329-04, Japan
The local structure of heme-iron of alkaline met-myoglobin during the thermal spin equilibrium between high and low spin states has been studied by a high resolution XANES. The spin-state sensitive near edge features have been found in the near threshold region, which are related to the distorted ligand field. The spin-state sensitive near-edge structures were also found for other myoglobin derivatives. From a systematic high resolution XANES study on MbCO, MbCN, and oxy-Mb, near-edge features which are sensitive to the angle between the diatomic ligand molecule and heme normal were found. These characteristic features can provide the elaborate local structure of heme-iron such as the displacement of iron atom from the heme plane or the bond angle of ligand molecule.