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The Electrically Wired Molybdenum Domain of Human Sulfite Oxidase is Bioelectrocatalytically Active

Spricigo, Roberto; Leimkuehler, Silke; Gorton, Lo LU ; Scheller, Frieder W. and Wollenberger, Ulla (2015) In European Journal of Inorganic Chemistry p.3526-3531
Abstract
We report electron transfer between the catalytic molybdenum cofactor (Moco) domain of human sulfite oxidase (hSO) and electrodes through a poly(vinylpyridine)-bound [osmium(N,N'-methyl-2,2'-biimidazole)(3)](2+/3+) complex as the electron-transfer mediator. The biocatalyst was immobilized in this low-potential redox polymer on a carbon electrode. Upon the addition of sulfite to the immobilized separate Moco domain, the generation of a significant catalytic current demonstrated that the catalytic center is effectively wired and active. The bioelectrocatalytic current of the wired separate catalytic domain reached 25% of the signal of the wired full molybdoheme enzyme hSO, in which the heme b(5) is involved in the electron-transfer pathway.... (More)
We report electron transfer between the catalytic molybdenum cofactor (Moco) domain of human sulfite oxidase (hSO) and electrodes through a poly(vinylpyridine)-bound [osmium(N,N'-methyl-2,2'-biimidazole)(3)](2+/3+) complex as the electron-transfer mediator. The biocatalyst was immobilized in this low-potential redox polymer on a carbon electrode. Upon the addition of sulfite to the immobilized separate Moco domain, the generation of a significant catalytic current demonstrated that the catalytic center is effectively wired and active. The bioelectrocatalytic current of the wired separate catalytic domain reached 25% of the signal of the wired full molybdoheme enzyme hSO, in which the heme b(5) is involved in the electron-transfer pathway. This is the first report on a catalytically active wired molybdenum cofactor domain. The formal potential of this electrochemical mediator is between the potentials of the two cofactors of hSO, and as hSO can occupy several conformations in the polymer matrix, it is imaginable that electron transfer from the catalytic site to the electrode through the osmium center occurs for the hSO molecules in which the Moco domain is sufficiently accessible. The observation of catalytic oxidation currents at low potentials is favorable for applications in bioelectronic devices. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Metalloenzymes, Enzyme catalysis, Immobilization, Osmium
in
European Journal of Inorganic Chemistry
issue
21
pages
3526 - 3531
publisher
John Wiley & Sons
external identifiers
  • wos:000359297800017
  • scopus:84938206331
ISSN
1099-0682
DOI
10.1002/ejic.201500034
language
English
LU publication?
yes
id
3f0602b1-1a45-4483-86b3-1b1878800d75 (old id 7975545)
date added to LUP
2015-09-24 15:01:04
date last changed
2017-04-30 05:22:08
@article{3f0602b1-1a45-4483-86b3-1b1878800d75,
  abstract     = {We report electron transfer between the catalytic molybdenum cofactor (Moco) domain of human sulfite oxidase (hSO) and electrodes through a poly(vinylpyridine)-bound [osmium(N,N'-methyl-2,2'-biimidazole)(3)](2+/3+) complex as the electron-transfer mediator. The biocatalyst was immobilized in this low-potential redox polymer on a carbon electrode. Upon the addition of sulfite to the immobilized separate Moco domain, the generation of a significant catalytic current demonstrated that the catalytic center is effectively wired and active. The bioelectrocatalytic current of the wired separate catalytic domain reached 25% of the signal of the wired full molybdoheme enzyme hSO, in which the heme b(5) is involved in the electron-transfer pathway. This is the first report on a catalytically active wired molybdenum cofactor domain. The formal potential of this electrochemical mediator is between the potentials of the two cofactors of hSO, and as hSO can occupy several conformations in the polymer matrix, it is imaginable that electron transfer from the catalytic site to the electrode through the osmium center occurs for the hSO molecules in which the Moco domain is sufficiently accessible. The observation of catalytic oxidation currents at low potentials is favorable for applications in bioelectronic devices.},
  author       = {Spricigo, Roberto and Leimkuehler, Silke and Gorton, Lo and Scheller, Frieder W. and Wollenberger, Ulla},
  issn         = {1099-0682},
  keyword      = {Metalloenzymes,Enzyme catalysis,Immobilization,Osmium},
  language     = {eng},
  number       = {21},
  pages        = {3526--3531},
  publisher    = {John Wiley & Sons},
  series       = {European Journal of Inorganic Chemistry},
  title        = {The Electrically Wired Molybdenum Domain of Human Sulfite Oxidase is Bioelectrocatalytically Active},
  url          = {http://dx.doi.org/10.1002/ejic.201500034},
  year         = {2015},
}