Weiss, SA, Bushby, RJ, Evans, SD et al. (1 more author) (2010) A study of cytochrome bo(3) in a tethered bilayer lipid membrane. BBA - Bioenergetics, 1797 (12). 1917 - 1923. ISSN 0005-2728
Abstract
An assay has been developed in which the activity of an ubiquinol oxidase from Escherichia coli, cytochrome bo3 (cbo3), is determined as a function of the hydrophobic substrate ubiquinol-10 (UQ-10) in tethered bilayer lipid membranes (tBLMs). UQ-10 was added in situ, while the enzyme activity and the UQ-10 concentration in the membrane have been determined by cyclic voltammetry. Cbo3 is inhibited by UQ-10 at concentrations above 5–10 pmol/cm2, while product inhibition is absent. Cyclic voltammetry has also been used to characterise the effects of three inhibitors; cyanide, inhibiting oxygen reduction; 2-n-Heptyl-4-hydroxyquinoline N-oxide (HQNO), inhibiting the quinone oxidation and Zn(II), thought to block the proton channels required for oxygen reduction and proton pumping activity. The electrochemical behaviour of cbo3 inhibited with HQNO and Zn(II) is almost identical, suggesting that Zn(II) ions inhibit the enzyme reduction by quinol, rather than oxygen reduction. This suggests that at Zn(II) concentration below 50 µM the proton release of cbo3 is inhibited, but not the proton uptake required to reduce oxygen to water.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | NOTICE: this is the author’s version of a work that was accepted for publication in BBA - Bioenergetics. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in BBA - Bioenergetics, 1797 (12), 2010, 10.1016/j.bbabio.2010.01.012 (c) 2010, Elsevier. This is an author produced version of a paper published in BBA - Bioenergetics. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Ubiquinol oxidase; Cytochrome c oxidase; Electrochemistry; Tethered bilayer lipid membrane; Enzyme mechanism; Aerobic Respiratory-Chain; Escherichia-Coli; Binding-Site; Q(H) Site; C-Oxidase; Terminal Oxidases; Electron-Transfer; Bo Complex; Ubiquinol; Purification |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemistry (Leeds) The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Physics and Astronomy (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 22 Nov 2013 10:57 |
Last Modified: | 07 Feb 2018 21:51 |
Published Version: | http://dx.doi.org/10.1016/j.bbabio.2010.01.012 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.bbabio.2010.01.012 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:77057 |