Helmholtz Gemeinschaft


Intermediates in the reaction of substrate-free cytochrome P450cam with peroxy acetic acid

Item Type:Article
Title:Intermediates in the reaction of substrate-free cytochrome P450cam with peroxy acetic acid
Creators Name:Schuenemann, V. and Jung, C. and Trautwein, A.X. and Mandon, D. and Weiss, R.
Abstract:Freeze-quenched intermediates of substrate-free cytochrome 57Fe-P450(cam) in reaction with peroxy acetic acid as oxidizing agent have been characterized by EPR and Mossbauer spectroscopy. After 8 ms of reaction time the reaction mixture consists of ~90% of ferric low-spin iron with g-factors and hyperfine parameters of the starting material; the remaining ~10% are identified as a free radical (S'=1/2) by its EPR and as an iron(IV) (S=1) species by its Mossbauer signature. After 5 min of reaction time the intermediates have disappeared and the Mossbauer and EPR-spectra exhibit 100% of the starting material. We note that the spin-Hamiltonian analysis of the spectra of the 8 ms reactant clearly reveals that the two paramagnetic species, e.g. the ferryl (iron(IV)) species and the radical, are not exchanged coupled. This led to the conclusion that under the conditions used, peroxy acetic acid oxidized a tyrosine residue (probably Tyr-96) into a tyrosine radical (Tyr( .)-96), and the iron(III) center of substrate-free P450(cam) to iron(IV). Copyright (C) 2000 Federation of European Biochemical Societies.
Keywords:Cytochrome P450(cam), Mossbauer Spectrum, Peroxy Acetic Acid
Source:FEBS Letters
Page Range:149-154
Date:1 January 2000
Official Publication:https://doi.org/10.1016/S0014-5793(00)01886-X
PubMed:View item in PubMed

Repository Staff Only: item control page

Open Access
MDC Library