Linked Life Data

2554962

Source:http://linkedlifedata.com/resource/pubmed/id/2554962

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
1990-1-5
pubmed:abstractText
Intramolecular electron transfer in partially reduced cytochrome c oxidase has been studied by the perturbed equilibrium method. We have prepared a three-electron-reduced, CO-inhibited form of the enzyme in which cytochrome a and copper A are partially reduced and in an intramolecular redox equilibrium. When these samples were irradiated with a nitrogen laser (0.6-ns, 1.0-mJ pulses) to photodissociate the bound CO, changes in absorbance at 598 and 830 nm were observed which were consistent with a fast electron transfer from cytochrome a to copper A. The absorbance changes at 598 nm gave an apparent rate of 17,000 +/- 2000 s-1 (1 sigma), at pH 7.0 and 25.5 degrees C. These changes were not observed in either the CO mixed-valence or the CO-inhibited fully reduced forms of the enzyme. The rate was fastest at about pH 8.0, falling off toward both lower and higher pHs. There was a small but clear temperature dependence. The process was also observed in the cytochrome c-cytochrome c oxidase high-affinity complex. The electron equilibration measured between cytochrome a and copper A is far faster than any rate measured or inferred previously for this process.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
28
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6975-83
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Electron transfer between cytochrome a and copper A in cytochrome c oxidase: a perturbed equilibrium study.
pubmed:affiliation
Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena 91125.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.