Linked Life Data

17388530

Source:http://linkedlifedata.com/resource/pubmed/id/17388530

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
14
pubmed:dateCreated
2007-4-5
pubmed:abstractText
The complex formed between cytochrome c oxidase from Paracoccus denitrificans and its electron-transfer partner cytochrome c has been studied by multi-frequency pulse electron paramagnetic resonance spectroscopy. The dipolar relaxation of a fast-relaxing paramagnetic center induced on a more slowly relaxing center can be used to measure their distance in the range of 1-4 nm. This method has been used here for the first time to study transient protein-protein complex formation, employing soluble fragments for both interacting species. We observed significantly enhanced transversal relaxation of the CuA center in cytochrome c oxidase due to the fast-relaxing iron of cytochrome c upon complex formation. The possibility to measure cytochrome c oxidase in the presence and absence of cytochrome c permitted us to separate the dipolar relaxation from other relaxation contributions. This allowed a quantitative simulation and interpretation of the relaxation data. The specific temperature dependence of the dipolar relaxation together with the high orientational selectivity achieved at high magnetic field values may provide detailed information on distance and relative orientation of the two proteins with respect to each other in the complex. Our experimental results cannot be explained by any single well-defined structure of the complex of cytochrome c oxidase with cytochrome c, but rather suggest that a broad distribution in distances and relative orientations between the two proteins exist within this complex.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1520-6106
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
111
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3839-46
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Protein-protein interactions studied by EPR relaxation measurements: cytochrome c and cytochrome c oxidase.
pubmed:affiliation
Institute of Physical and Theoretical Chemistry, Institute of Biochemistry, Center for Biomolecular Magnetic Resonance, and Center of Excellence "Macromolecular Complexes", Johann Wolfgang Goethe University, Frankfurt am Main, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't