Electron-transfer rates govern product distribution in electrochemically- driven P450-catalyzed dioxygen reduction

Clairisse Van Der Felt, Kevork Hindoyan, Kang Choi, Nazafarin Javdan, Peter Goldman, Rose Bustos, Andrew G. Star, Bryan M. Hunter, Michael G. Hill, Aram Nersissian, Andrew K. Udit*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

11 Scopus citations


Developing electrode-driven biocatalytic systems utilizing the P450 cytochromes for selective oxidations depends not only on achieving electron transfer (ET) but also doing so at rates that favor native-like turnover. Herein we report studies that correlate rates of heme reduction with ET pathways and resulting product distributions. We utilized single-surface cysteine mutants of the heme domain of P450 from Bacillus megaterium and modified the thiols with N-(1-pyrene)-iodoacetamide, affording proteins that could bond to basal-plane graphite. Of the proteins examined, Cys mutants at position 62, 383, and 387 were able to form electroactive monolayers with similar E 1/2 values (- 335 to - 340 mV vs AgCl/Ag). Respective ET rates (k s o) and heme-cysteine distances for 62, 383, and 387 are 50 s -1 and 16 Å, 0.8 s - 1 and 25 Å, and 650 s - 1 and 19 Å. Experiments utilizing rotated-disk electrodes were conducted to determine the products of P450-catalyzed dioxygen reduction. We found good agreement between ET rates and product distributions for the various mutants, with larger k s o values correlating with more electrons transferred per dioxygen during catalysis.

Original languageEnglish (US)
Pages (from-to)1350-1353
Number of pages4
JournalJournal of Inorganic Biochemistry
Issue number10
StatePublished - Oct 2011


  • Biocatalysis
  • Cytochrome P450
  • Dioxygen reduction
  • Electrochemistry
  • Electron transfer

ASJC Scopus subject areas

  • Biochemistry
  • Inorganic Chemistry


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