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Published on: July 4, 2016
The high-spin/low-spin equilibrium in cytochrome P-450--a new method for determination of the high-spin content
1Central Institute of Molecular Biology, Academy of Sciences of the G.D.R., Berlin.
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.
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