Linked Life Data

2550057

Source:http://linkedlifedata.com/resource/pubmed/id/2550057

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
13
pubmed:dateCreated
1989-10-13
pubmed:abstractText
Cytochrome oxidase from yeast has been covalently labeled with a nitroxide derivative of maleimide and reconstituted in lipid-substituted complexes with dimyristoyl-, dioleoyl-, or dielaidoyl-phosphatidylcholine. The rotational mobility of the enzyme in the complexes has been studied as a function of temperature and time, and of lipid/protein ratio, using saturation-transfer electron spin resonance spectroscopy. For complexes with dimyristoylphosphatidylcholine, the rotational mobility of the protein decreases abruptly below the gel-to-fluid-phase transition. This change is accompanied by a lateral segregation of the protein, as seen by freeze-fracture electron microscopy, and by an increase in the activation energy for the enzymatic activity. A time-dependent decrease in the rotational motion of the protein is observed on incubating at temperatures in the fluid phase of the lipid. This corresponds with a time-dependent loss of enzyme activity observed on incubation at temperatures in the fluid phase, but not at temperatures in the gel phase, over a period of 3 h. The rotational mobility decreases with increasing protein concentration in the complexes, both in the fluid and in the gel phases. The dependence of the protein mobility on lipid/protein ratio can be interpreted quantitatively in terms of the effect of increased random protein-protein contacts in the fluid phase. The maximum limiting rotational correlation time for the protein diffusion at high lipid/protein ratios in the fluid phase is tau R[[ approximately equal to 25 microseconds, suggesting that the protein is present as either a monomer or more probably a dimer in the reconstituted membrane.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
28
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5634-43
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Rotational motion of yeast cytochrome oxidase in phosphatidylcholine complexes studied by saturation-transfer electron spin resonance.
pubmed:affiliation
Max-Planck-Institut für biophysikalische Chemie, Abteilung Spektroskopie, Göttingen, Federal Republic of Germany.
pubmed:publicationType
Journal Article