Proton Transport in the Outer-Membrane Flavocytochrome Complex Limits the Rate of Extracellular Electron Transport

Akihiro Okamoto*, Yoshihide Tokunou, Shafeer Kalathil, Kazuhito Hashimoto

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

27 Citations (Scopus)
3 Downloads (Pure)

Abstract

The microbial transfer of electrons to extracellularly located solid compounds, termed extracellular electron transport (EET), is critical for microbial electrode catalysis. Although the components of the EET pathway in the outer membrane (OM) have been identified, the role of electron/cation coupling in EET kinetics is poorly understood. We studied the dynamics of proton transport associated with EET in an OM flavocytochrome complex in Shewanella oneidensis MR-1. Using a whole-cell electrochemical assay, a significant kinetic isotope effect (KIE) was observed following the addition of deuterated water (D2O). The removal of a flavin cofactor or key components of the OM flavocytochrome complex significantly increased the KIE in the presence of D2O to values that were significantly larger than those reported for proton channels and ATP synthase, thus indicating that proton transport by OM flavocytochrome complexes limits the rate of EET.

Original languageEnglish
Pages (from-to)9082-9086
Number of pages5
JournalAngewandte Chemie - International Edition
Volume56
Issue number31
Early online date29 Jun 2017
DOIs
Publication statusPublished - 24 Jul 2017
Externally publishedYes

Fingerprint

Dive into the research topics of 'Proton Transport in the Outer-Membrane Flavocytochrome Complex Limits the Rate of Extracellular Electron Transport'. Together they form a unique fingerprint.

Cite this