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Site-directed immobilization of bilirubin oxidase for electrocatalytic oxygen reduction

Site-directed immobilization of bilirubin oxidase for electrocatalytic oxygen reduction
Site-directed immobilization of bilirubin oxidase for electrocatalytic oxygen reduction
In this work we extended the generic approach for the site-directed immobilization of enzymes based on maleimide\thiol coupling of engineered enzymes to the oriented immobilization of variants of bilirubin oxidase from Magnaporthe oryzae (MoBOD) to electrodes. We show that this approach leads to the stable attachment of the enzyme to the electrode surface and that the immobilised MoBOD variants are active for bioelectrocatalytic reduction of di-oxygen through direct (unmediated) electron transfer (DET) from the electrode. For the three MoBOD variants studied significant differences are observed in the kinetics of DET that relate to the orientation of the enzyme and the distance of the T1 site from the electrode surface. The stability of the immobilized enzymes allows us to compare the DET and mediated electron transfer (MET) pathways and to investigate the effects of pH and Cl‾. Our studies show a change in the slope of pH dependence at pH 6.0 and highlight the effect of Cl‾ on the direct oxygen reduction by MoBOD as a function of pH for the immobilized enzyme and the interconversion of the resting oxidized (RO) form of the immobilized enzyme and the alternative resting (AR) state formed in the presence of Cl‾.
bilirubin oxidase, direct electron transfer, oxygen reduction, site directed mutagenesis, immobilization, maleimide
2155-5435
2068-2078
Al-Lolage, Firas
83184275-ce0e-4887-aee4-4b4c81bf7c06
Bartlett, Philip N.
d99446db-a59d-4f89-96eb-f64b5d8bb075
Gounel, Sebastien
ddd5e895-80f7-4cde-90c1-3c1fdba153e5
Staigre, Priscilla
119095e1-049a-4a24-8197-ccbfdd579f48
Mano, Nicolas
6ab1d48d-9db4-4f05-a68d-b684d0602dbe
Al-Lolage, Firas
83184275-ce0e-4887-aee4-4b4c81bf7c06
Bartlett, Philip N.
d99446db-a59d-4f89-96eb-f64b5d8bb075
Gounel, Sebastien
ddd5e895-80f7-4cde-90c1-3c1fdba153e5
Staigre, Priscilla
119095e1-049a-4a24-8197-ccbfdd579f48
Mano, Nicolas
6ab1d48d-9db4-4f05-a68d-b684d0602dbe

Al-Lolage, Firas, Bartlett, Philip N., Gounel, Sebastien, Staigre, Priscilla and Mano, Nicolas (2019) Site-directed immobilization of bilirubin oxidase for electrocatalytic oxygen reduction. ACS Catalysis, 9 (3), 2068-2078. (doi:10.1021/acscatal.8b04340).

Record type: Article

Abstract

In this work we extended the generic approach for the site-directed immobilization of enzymes based on maleimide\thiol coupling of engineered enzymes to the oriented immobilization of variants of bilirubin oxidase from Magnaporthe oryzae (MoBOD) to electrodes. We show that this approach leads to the stable attachment of the enzyme to the electrode surface and that the immobilised MoBOD variants are active for bioelectrocatalytic reduction of di-oxygen through direct (unmediated) electron transfer (DET) from the electrode. For the three MoBOD variants studied significant differences are observed in the kinetics of DET that relate to the orientation of the enzyme and the distance of the T1 site from the electrode surface. The stability of the immobilized enzymes allows us to compare the DET and mediated electron transfer (MET) pathways and to investigate the effects of pH and Cl‾. Our studies show a change in the slope of pH dependence at pH 6.0 and highlight the effect of Cl‾ on the direct oxygen reduction by MoBOD as a function of pH for the immobilized enzyme and the interconversion of the resting oxidized (RO) form of the immobilized enzyme and the alternative resting (AR) state formed in the presence of Cl‾.

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Accepted/In Press date: 1 January 2019
e-pub ahead of print date: 22 January 2019
Published date: March 2019
Keywords: bilirubin oxidase, direct electron transfer, oxygen reduction, site directed mutagenesis, immobilization, maleimide

Identifiers

Local EPrints ID: 428161
URI: http://eprints.soton.ac.uk/id/eprint/428161
ISSN: 2155-5435
PURE UUID: fc526d27-64ff-4d7f-8905-0ef02414bc16
ORCID for Philip N. Bartlett: ORCID iD orcid.org/0000-0002-7300-6900

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Date deposited: 13 Feb 2019 17:30
Last modified: 16 Mar 2024 07:34

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Contributors

Author: Firas Al-Lolage
Author: Sebastien Gounel
Author: Priscilla Staigre
Author: Nicolas Mano

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