Modifications on the hydrogen bond network by mutations of Escherichia coli copper efflux oxidase affect the process of proton transfer to dioxygen leading to alterations of enzymatic activities

• Kajikawa, Takao

• Kataoka, Kunishige

• Sakurai, Takeshi

抄録

CueO has a branched hydrogen bond network leading from the exterior of the protein molecule to the trinuclear copper center. This network transports protons in the four-electron reduction of dioxygen. We replaced the acidic Glu506 and Asp507 residues with the charged and uncharged amino acid residues. Peculiar changes in the enzyme activity of the mutants relative to the native enzyme indicate that an acidic amino acid residue at position 506 is essential for effective proton transport. The Ala mutation resulted in the formation of a compensatory hydrogen bond network with one or two extra water molecules. On the other hand, the Ile mutation resulted in the complete shutdown of the hydrogen bond network leading to loss of enzymatic activities of CueO. In contrast, the hydrogen bond network without the proton transport function was constructed by the Gln mutation. These results exerted on the hydrogen bond network in CueO are discussed in comparison with proton transfers in cytochrome oxidase. © 2012 Elsevier Inc.

収録刊行物

• Biochemical and Biophysical Research Communications

  Biochemical and Biophysical Research Communications 422 (1), 152-156, 2012-05-25

  Elsevier

キーワード

• CueO
• Hydrogen bond network
• Multicopper oxidas
• O 2-reduction
• Proton transfer

詳細情報

• CRID: 1050845760872478464
• NII論文ID: 120004161530
• NII書誌ID: AA00564395
• ISSN: 0006291X
• Web Site: http://hdl.handle.net/2297/33409
• Web Site: http://hdl.handle.net/2297/31387
• 本文言語コード: en
• 資料種別: journal article
• データソース種別:
  • IRDB
  • CiNii Articles