Probing Electron Transfer in the Manganese-Oxide-Forming MnxEFG Protein Complex using Fourier Transformed AC Voltammetry: Understanding the Oxidative Priming Effect

Lizhi Tao, Alexandr N. Simonov, Christine A. Romano, Cristina N. Butterfield, Bradley M. Tebo, Alan M. Bond, Leone Spiccia, Lisandra L. Martin, William H. Casey

Research output: Contribution to journalArticle

3 Scopus citations

Abstract

MnxG, a multicopper oxidase, is an enzyme from the marine Bacillus species, which produces manganese oxide minerals through the aerobic oxidation of dissolved Mn2+ − a key process in global manganese geochemical cycling. When isolated in an active form as a part of the MnxEFG protein complex, the enzymatic activity of MnxG is substantially enhanced by mild oxidative priming. Herein, the mechanism for this effect is probed by using direct current (dc) and Fourier transformed alternating current (ac) voltammetric analysis of the MnxEFG complex and the catalytically inactive MnxEF subunit immobilised on a carbon electrode. Analysis of these ac voltammetric data reveals a significant enhancement in the rate of electron transfer in the Type 2 Cu sites upon oxidative priming of the enzyme, which is attributed to the improved catalytic activity of MnxG in the MnxEFG protein complex.

Original languageEnglish (US)
Pages (from-to)872-876
Number of pages5
JournalChemElectroChem
Volume5
Issue number6
DOIs
StatePublished - Mar 2018

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Keywords

  • Fourier transformed alternating current voltammetry
  • MnO mineralisation
  • direct current protein voltammetry
  • electron transfer
  • multicopper oxidase

ASJC Scopus subject areas

  • Catalysis
  • Electrochemistry

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