抄録
A number of 57Fe enriched peroxidase and its derivatives are investigated by the Mössbauer effect of heme-iron. Fluoride compound exhibited broad magnetic hyperfine splittings characteristic of ferric high-spin state. Hydroxide and azide compounds showed large quadrupole splittings resulting from ferric low-spin states. Free peroxidase and cyanide compound exhibited quadrupole splittings of strong temperature dependence. The temperature dependence of quadrupole splittings is too strong to be ascribed to (dε)5 state. The small quadrupole splitting and small isomer shift of cyanide compound are attributable to the covalent mixing of CN− and ferriciron. The reduced peroxidase exhibited large isomer shift and large quadrupole splitting of strong temperature dependence. These are the characteristics of ferrous high-spin state. Reduced carbon monoxide compound showed a small quadrupole splitting, which is attributable to ferrous low-spin state.
