Linked Life Data

12176061

Source:http://linkedlifedata.com/resource/pubmed/id/12176061

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2002-8-14
pubmed:abstractText
NADH dehydrogenase-2 (NDH-2) from Escherichia coli is a membrane-bound flavoprotein linked to the respiratory chain. We have previously shown that this enzyme has cupric reductase activity that is involved in hydroperoxide-induced oxidative stress. In this paper we present spectroscopic evidence that NDH-2 contains thiolate-bound Cu(I) with luminescence properties. Purified NDH-2 exhibits an emission band at 670nm with excitation wavelengths of 280 and 580nm. This emission is quenched by the specific Cu(I) chelator bathocuproine disulfonate, but not by EDTA. The luminescence intensity is sensitive to the enzyme substrates and, thus, the Cu(I)-thiolate chromophore reflects the redox and/or conformational states of the protein. There is one copper atom per polypeptide chain of the purified NDH-2, as determined by atomic absorption spectroscopy. Bioinformatics allowed us to recognize a putative copper-binding site and to predict four structural/functional domains in NDH-2: (I) the FAD-binding domain, (II) the NAD(H)-binding domain, (III) the copper-binding domain, and (IV) the domain of anchorage to the membrane containing two transmembrane helices, at the C-terminus. A NDH-2 topology model, based on the secondary structure prediction, is proposed. This is the first description of a copper-containing NADH dehydrogenase. Comparative sequence analysis allowed us to identify a branch of homologous dehydrogenases that bear a similar metal-binding motif.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0003-9861
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
405
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
87-94
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Evidence for Cu(I)-thiolate ligation and prediction of a putative copper-binding site in the Escherichia coli NADH dehydrogenase-2.
pubmed:affiliation
Departamento Bioquímica de la Nutrición, Instituto Superior de Investigaciones Biológicas, Universidad Nacional de Tucumán, Chacabuco 461, San Miguel de Tucumán, Argentina.
pubmed:publicationType
Journal Article