title: The high-spin/low-spin equilibrium in cytochrome P-450--a new method for determination of the high-spin content.
abstract: A new method for determination of the population of the high-spin state (high-spin content) in ferric cytochrome P-450 is presented. Based on curve fitting the electronic absorption spectra with a linear combination of gaussian bands analytical functions for the pure high-spin and pure low-spin states were constructed. These functions were used to fit the high-spin/low-spin mixed spectra. A good fit of the absorption spectra of six different cytochrome P-450 proteins in the presence and absence of substrates was found, indicating a similar pi-electron structure of the porphyrin and a similar chemical nature of the nearest coordination sphere of the iron in all cytochrome P-450 proteins.
authors.affiliation: Central Institute of Molecular Biology, Academy of Sciences of the G.D.R., Berlin.
authors.forename: C
authors.initials: C
authors.lastname: Jung
authors.forename: O
authors.initials: O
authors.lastname: Ristau
authors.forename: H
authors.initials: H
authors.lastname: Rein
mesh_terms: D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry* / Q000378:metabolism; D004578:Electron Spin Resonance Spectroscopy; D011817:Rabbits; D013054:Spectrophotometry, Atomic; D013816:Thermodynamics
chemical_list: D003577:Cytochrome P-450 Enzyme System