Effects of Elimination of α Helix Regions on Direct Electron Transfer-type Bioelectrocatalytic Properties of Copper Efflux Oxidase

• ADACHI Taiki

  Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University

• KITAZUMI Yuki

  Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University

• SHIRAI Osamu

  Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University

• KAWANO Tenta

  Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University

• KATAOKA Kunishige

  Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University

• KANO Kenji

  Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University

Bibliographic Information

Other Title

• Effects of elimination of a helix regions on direct electron transfer-type bioelectrocatalytic properties of copper efflux oxidase

Abstract

We investigated properties of direct electron transfer (DET)-type bioelectrocatalysis of recombinant native Copper efflux oxidase (rCueO) and its variants which lack α helices covering the electron-donating substrate-binding site (Δα5–7CueO, Δα5CueO, Δα6–7CueO, and Δα5–7+1/2α5CueO) at mesoporous carbon electrodes without pretreatment and modified with positively or negatively charged aromatic amines. Kinetic and thermodynamic parameters of the electrode reaction were obtained by analysis of steady-state catalytic waves based on a random orientation model and examined the results on the basis of the structural information of the enzymes. The data suggested that the electron transfer pathway is different from that in solution; electrons are transferred from an electrode to the T1 Cu site through the negatively charged position near the T1 Cu site in rCueO without passing through the α helix region in DET-type bioelectrocatalysis. Positively charged electrode was a suitable scaffold for DET-type reaction of rCueO. The T1 Cu site in Δα5CueO became somewhat hydrophobic and hydrophobic electrode worked as a suitable scaffold for the variant. Negatively charged electrode seems to induce unfavorable attractive orientation for DET-type reaction between the electrode and positively charged region of the CueOs on the opposite side of the T1 Cu site.

Journal

• Electrochemistry

  Electrochemistry 88 (3), 185-189, 2020-05-05

  The Electrochemical Society of Japan

Keywords

• Copper Efflux Oxidase
• Electrostatic Interaction
• Hydrophobic Interaction
• Electron Transfer Pathway

Details

• CRID: 1390003825179369728
• NII Article ID: 130007840148
• DOI: 10.5796/electrochemistry.20-00015
• ISSN: 21862451
• ISSN: 13443542
• Web Site: https://www.jstage.jst.go.jp/article/electrochemistry/88/3/88_20-00015/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Allowed