Linked Life Data

16704969

Source:http://linkedlifedata.com/resource/pubmed/id/16704969

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
29
pubmed:dateCreated
2006-7-17
pubmed:abstractText
In the reductive phase of its catalytic cycle, cytochrome c oxidase receives electrons from external electron donors. Two electrons have to be transferred into the catalytic center, composed of heme a(3) and Cu(B), before reaction with oxygen takes place. In addition, this phase of catalysis appears to be involved in proton translocation. Here, we report for the first time the kinetics of electron transfer to both heme a(3) and Cu(B) during the transition from the oxidized to the fully reduced state. The state of reduction of both heme a(3) and Cu(B) was monitored by a combination of EPR spectroscopy, the rapid freeze procedure, and the stopped-flow method. The kinetics of cytochrome c oxidase reduction by hexaamineruthenium under anaerobic conditions revealed that the rate-limiting step is the initial electron transfer to the catalytic site that proceeds with apparently identical rates to both heme a(3) and Cu(B). After Cu(B) is reduced, electron transfer to oxidized heme a(3) is enhanced relative to the rate of entry of the first electron.
pubmed:grant
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
21
pubmed:volume
281
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
20003-10
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Filling the catalytic site of cytochrome c oxidase with electrons. Reduced CuB facilitates internal electron transfer to heme a3.
pubmed:affiliation
Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77005, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural