Format

Send to

Choose Destination
See comment in PubMed Commons below
Biochem Biophys Res Commun. 2004 Dec 24;325(4):1418-23.

The unusual redox properties of flavocytochrome P450 BM3 flavodoxin domain.

Author information

  • 1School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, UK.

Abstract

Flavocytochrome P450 BM3 FMN domain is unique among the family of flavodoxins and homologues, in not forming a stable neutral blue FMN semiquinone radical. Anaerobic, one-electron reduction of the isolated domain over the pH 7-9.5 range showed that it forms an anionic red semiquinone that disproportionates slowly (0.014s(-1) at pH 7). The rate of disproportionation decreased at higher pH, indicating that protonation of the anionic semiquinone is an important feature of the mechanism. The reduction potential for the oxidised-semiquinone couple was determined to be -240mV and was largely independent of pH. The semiquinone appears, therefore, to be kinetically trapped by a slow protonation event, enabling it to act as a low-potential electron donor to the P450 heme.

PMID:
15555585
DOI:
10.1016/j.bbrc.2004.10.189
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Support Center