Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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Record number 327012
Title Molecular characterization of H2O2-forming NADH oxidases from Archeaoglobus fulgidus
Author(s) Kengen, S.W.M.; Oost, J. van der; Vos, W.M. de
Source European Journal of Biochemistry 270 (2003)13. - ISSN 0014-2956 - p. 2885 - 2894.
DOI http://dx.doi.org/10.1046/j.1432-1033.2003.03668.x
Department(s) Microbiological Laboratory
VLAG
Publication type Refereed Article in a scientific journal
Publication year 2003
Keyword(s) flavoprotein disulfide reductases - streptococcus-faecalis 10c1 - thermus-thermophilus hb8 - pyrococcus-furiosus - escherichia-coli - elemental sulfur - cloning - gene - purification - sequence
Abstract Three NADH oxidase encoding genes noxA-1 , noxB-1 and noxC were cloned from the genome of Archaeoglobus fulgidus , expressed in Escherichia coli , and the gene products were purified and characterized. Expression of noxA-1 and noxB-1 resulted in active gene products of the expected size. The noxC gene was expressed as well but the protein produced showed no activity in the standard Nox assay. NoxA-1 and NoxB-1 are both FAD-containing enzymes with subunit molecular masses of 48 and 69 kDa, respectively. NoxA-1 exists predominantly as homodimer, NoxB-1 as monomer. NoxA-1 and NoxB-1 showed pH optimum of 8.0 and 6.5, with specific NADH oxidase activities of 5.8 U.mg(-1) and 4.1 U.mg(-1) , respectively. Both enzymes were specific for NADH as electron donor, but with different apparent K (m) values (NoxA-1, 0.13 mm; NoxB-1, 0.011 mm). The apparent K (m) values for oxygen differed significantly (NoxA-1, 0.06 mm; NoxB-1, 2.9 mm). In contrast with all mesophilic homologues, both enzymes were found to produce predominantly H-2 O-2 instead of H-2 O. Despite apparent similarities, NoxB-1 is essentially different from NoxA-1. Whereas NoxA-1 resembles typical H-2 O-producing Nox enzymes that are expected to have a role in oxidative stress defence, NoxB-1 belongs to a small group of enzymes that is involved in catalysing the reduction of unsaturated acids and aldehydes, suggesting a role in fatty acid oxidation. Moreover, NoxB-1 contains a ferredoxin-like motif, which is absent in NoxA-1.
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