Linked Life Data

10903524

Source:http://linkedlifedata.com/resource/pubmed/id/10903524

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
15
pubmed:dateCreated
2000-9-28
pubmed:abstractText
Here we provide evidence that mitochondria isolated from rat liver can synthesize FAD from riboflavin that has been taken up and from endogenous ATP. Riboflavin uptake takes place via a carrier-mediated process, as shown by the inverse relationship between fold accumulation and riboflavin concentration, the saturation kinetics [riboflavin Km and Vmax values were 4.4+/-1.3 microM and 35+/-5 pmol x min(-1) (mg protein)(-1), respectively] and the inhibition shown by the thiol reagent mersalyl, which cannot enter the mitochondria. FAD synthesis is due to the existence of FAD synthetase (EC 2.7.7.2), localized in the matrix, which has as a substrate pair mitochondrial ATP and FMN synthesized from taken up riboflavin via the putative mitochondrial riboflavin kinase. In the light of certain features, including the protein thermal stability and molecular mass, mitochondrial FAD synthetase differs from the cytosolic isoenzyme. Apparent Km and apparent Vmax values for FMN were 5.4+/-0.9 microM and 22.9+/-1.4 pmol x min(-1) x (mg matrix protein)(-1), respectively. Newly synthesized FAD inside the mitochondria can be exported from the mitochondria in a manner sensitive to atractyloside but insensitive to mersalyl. The occurrence of the riboflavin/FAD cycle is proposed to account for riboflavin uptake in mitochondria biogenesis and riboflavin recovery in mitochondrial flavoprotein degradation; both are prerequisites for the synthesis of mitochondrial flavin cofactors.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:volume
267
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4888-900
pubmed:dateRevised
2007-7-23
pubmed:meshHeading
pubmed-meshheading:10903524-Animals, pubmed-meshheading:10903524-Atractyloside, pubmed-meshheading:10903524-Chromatography, Gel, pubmed-meshheading:10903524-Cytosol, pubmed-meshheading:10903524-Dose-Response Relationship, Drug, pubmed-meshheading:10903524-Enzyme Inhibitors, pubmed-meshheading:10903524-Flavin-Adenine Dinucleotide, pubmed-meshheading:10903524-Glutamate Dehydrogenase, pubmed-meshheading:10903524-Kinetics, pubmed-meshheading:10903524-L-Lactate Dehydrogenase, pubmed-meshheading:10903524-Male, pubmed-meshheading:10903524-Mitochondria, Liver, pubmed-meshheading:10903524-Models, Biological, pubmed-meshheading:10903524-Nucleotidyltransferases, pubmed-meshheading:10903524-Phosphotransferases (Alcohol Group Acceptor), pubmed-meshheading:10903524-Rats, pubmed-meshheading:10903524-Rats, Wistar, pubmed-meshheading:10903524-Riboflavin, pubmed-meshheading:10903524-Time Factors
pubmed:year
2000
pubmed:articleTitle
The riboflavin/FAD cycle in rat liver mitochondria.
pubmed:affiliation
Dipartimento di Biochimica e Biologia Molecolare, Università di Bari, and Centro di Studio sui Mitocondri e Metabolismo Energetico, Bari, C.N.R., Italy. m.barile@biologia.uniba.it
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't