Linked Life Data

19088074

Source:http://linkedlifedata.com/resource/pubmed/id/19088074

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2009-2-9
pubmed:abstractText
Mutations in the genes encoding the alpha-subunit and beta-subunit of the mitochondrial electron transfer flavoprotein (ETF) and the electron transfer flavoprotein:ubiquinone oxidoreductase (ETF:QO) cause multiple acyl-CoA dehydrogenation deficiency (MADD), a disorder of fatty acid and amino acid metabolism. Point mutations in ETF, which may compromise folding, and/or activity, are associated with both mild and severe forms of MADD. Here we report the investigation on the conformational and stability properties of the disease-causing variant ETFbeta-D128N, and our findings on the effect of flavinylation in modulating protein conformational stability and activity. A combination of biochemical and biophysical methods including circular dichroism, visible absorption, flavin, and tryptophan fluorescence emission allowed the analysis of structural changes and of the FAD moiety. The ETFbeta-D128N variant retains the overall fold of the wild type, but under stress conditions its flavin becomes less tightly bound. Flavinylation is shown to improve the conformational stability and biological activity of a destabilized D128N variant protein. Moreover, the presence of flavin prevented proteolytic digestion by avoiding protein destabilization. A patient homozygous for the ETFbeta-D128N mutation developed severe disease symptoms in association with a viral infection and fever. In agreement, our results suggest that heat inactivation of the mutant may be more relevant at temperatures above 37 degrees C. To mimic a situation of fever in vitro, the flavinylation status was tested at 39 degrees C. FAD exerts the effect of a pharmacological chaperone, improving ETF conformation, and yielding a more stable and active enzyme. Our results provide a structural and functional framework that could help to elucidate the role that an increased cellular FAD content obtained from riboflavin supplementation may play in the molecular pathogenesis of not only MADD, but genetic disorders of flavoproteins in general.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
13
pubmed:volume
284
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4222-9
pubmed:meshHeading
pubmed-meshheading:19088074-Amino Acid Substitution, pubmed-meshheading:19088074-Amino Acids, pubmed-meshheading:19088074-Circular Dichroism, pubmed-meshheading:19088074-Electron Transport Complex I, pubmed-meshheading:19088074-Electron-Transferring Flavoproteins, pubmed-meshheading:19088074-Fatty Acids, pubmed-meshheading:19088074-Flavin-Adenine Dinucleotide, pubmed-meshheading:19088074-Homozygote, pubmed-meshheading:19088074-Hot Temperature, pubmed-meshheading:19088074-Humans, pubmed-meshheading:19088074-Multiple Acyl Coenzyme A Dehydrogenase Deficiency, pubmed-meshheading:19088074-Point Mutation, pubmed-meshheading:19088074-Protein Folding, pubmed-meshheading:19088074-Protein Stability, pubmed-meshheading:19088074-Protein Structure, Tertiary, pubmed-meshheading:19088074-Riboflavin, pubmed-meshheading:19088074-Structure-Activity Relationship
pubmed:year
2009
pubmed:articleTitle
Role of flavinylation in a mild variant of multiple acyl-CoA dehydrogenation deficiency: a molecular rationale for the effects of riboflavin supplementation.
pubmed:affiliation
Instituto Tecnologia Química e Biológica, Universidade Nova de Lisboa, 2780-756 Oeiras, Portugal.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't