Linked Life Data

2840124

Source:http://linkedlifedata.com/resource/pubmed/id/2840124

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1988-9-1
pubmed:abstractText
Bovine heart mitochondrial complex III (ubiquinol-cytochrome-c reductase) has been reconstituted into phosphatidylcholine bilayers and the effect of varying lipid/protein ratios on the structure and function of the protein has been examined. Electron microscopy, differential scanning calorimetry and Arrhenius plots of enzyme activity provide evidence that the protein is incorporated in an active conformation into pure phosphatidylcholine bilayers. At low lipid/protein ratios (e.g. 80:1 molar ratio) the protein exists in the form of aggregates. As the lipid proportion is increased, electron microscopy reveals the gradual formation of lipid bilayers; structures with the appearance of closed vesicles are seen at or above 300:1 phospholipid/protein molar ratios. Changes in enzyme activity as a function of lipid contents reveal a progressive increase in activity as more lipid is added, with a tendency to reach a saturation point. From the experimental data, a kinetic model is proposed, according to which the protein has an indefinite number of unspecific, independent and identical binding sites for phospholipids, the latter acting as essential enzyme activators. Varying lipid/protein ratios induce structural changes in complex III; visible spectra indicate changes in the polarity of the heme group environment, while Fourier-transform infrared spectroscopy suggests a change in the secondary structure of the protein as the lipid proportion is increased.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
21
pubmed:volume
942
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
341-52
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Lipid-protein interactions. The mitochondrial complex III-phosphatidylcholine-water system.
pubmed:affiliation
Department of Biochemistry, Faculty of Science, University of the Basque Country, Bilbao, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't