Source:http://linkedlifedata.com/resource/pubmed/id/11460922
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
1
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| pubmed:dateCreated |
2001-7-19
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| pubmed:abstractText |
A new type-II NADH dehydrogenase (NDH-II) was isolated from the hyperthermoacidophilic archaeon Acidianus ambivalens. This enzyme is a monomer with an apparent molecular mass of 47 kDa, containing a covalently bound flavin, and no iron-sulfur clusters. Upon isolation, NDH-II loses activity, which can, nevertheless, be restored by incubation with phospholipids. Catalytically, it is a proficient NADH:caldariella quinone oxidoreductase (130 mmol NADH oxidized/mg protein(-1)/min(-1)) but it can also donate electrons to synthetic quinones, strongly suggesting its involvement in the respiratory chain. The apparent Km for NADH was found to be approximately 6 microM, both for the purified and membrane-integrated enzyme, thus showing that detergent solubilization and purification did not affect the substrate binding site. Further, it is the first example of a type-II NADH dehydrogenase that contains the flavin covalently attached, which may be related to the need to stabilize the otherwise labile cofactor in a thermophilic environment. A fully operative minimal version of Acidianus ambivalens respiratory system was successfully reconstituted into artificial liposomes, using three basic components isolated from the organism: the type-II NADH dehydrogenase, caldariella quinone, the organism-specific quinone, and the aa3 type quinol oxidase. This system, which mimics the in vivo chain, is efficiently energized by NADH, driving oxygen consumption by means of the terminal oxidase.
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:citationSubset |
IM
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| pubmed:chemical | |
| pubmed:status |
MEDLINE
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| pubmed:month |
Feb
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| pubmed:issn |
0145-479X
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:volume |
33
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
1-8
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| pubmed:dateRevised |
2008-11-21
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| pubmed:meshHeading |
pubmed-meshheading:11460922-Amino Acid Sequence,
pubmed-meshheading:11460922-Chemistry, Physical,
pubmed-meshheading:11460922-Electron Transport,
pubmed-meshheading:11460922-Kinetics,
pubmed-meshheading:11460922-Molecular Sequence Data,
pubmed-meshheading:11460922-Molecular Weight,
pubmed-meshheading:11460922-NADH Dehydrogenase,
pubmed-meshheading:11460922-Oxidation-Reduction,
pubmed-meshheading:11460922-Physicochemical Phenomena,
pubmed-meshheading:11460922-Sequence Homology, Amino Acid,
pubmed-meshheading:11460922-Sulfolobaceae
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| pubmed:year |
2001
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| pubmed:articleTitle |
A new type-II NADH dehydrogenase from the archaeon Acidianus ambivalens: characterization and in vitro reconstitution of the respiratory chain.
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| pubmed:affiliation |
Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal.
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| pubmed:publicationType |
Journal Article
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