Linked Life Data

19592112

Source:http://linkedlifedata.com/resource/pubmed/id/19592112

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2009-8-3
pubmed:abstractText
Inhibition of terminal oxidases by nitric oxide (NO) has been extensively investigated as it plays a role in regulation of cellular respiration and pathophysiology. Cytochrome bd is a tri-heme (b(558), b(595), d) bacterial oxidase containing no copper that couples electron transfer from quinol to O(2) (to produce H(2)O) with generation of a transmembrane protonmotive force. In this work, we investigated by stopped-flow absorption spectroscopy the reaction of NO with Escherichia coli cytochrome bd in the fully oxidized (O) state. We show that under anaerobic conditions, the O state of the enzyme binds NO at heme d with second-order rate constant k(on)=1.5+/-0.2x10(2) M(-1) s(-1), yielding a nitrosyl adduct (d(3+)-NO or d(2+)-NO(+)) with characteristic optical features (an absorption increase at 639nm and a red shift of the Soret band). The reaction mechanism is remarkably different from that of O cytochrome c oxidase in which the heme-copper binuclear center reacts with NO approximately three orders of magnitude faster, forming nitrite. The data allow us to conclude that in the reaction of NO with terminal oxidases in the O state, Cu(B) is indispensable for rapid oxidation of NO into nitrite.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1873-3344
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
103
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1185-7
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Reaction of nitric oxide with the oxidized di-heme and heme-copper oxygen-reducing centers of terminal oxidases: Different reaction pathways and end-products.
pubmed:affiliation
Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Russian Federation.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't