Linked Life Data

10548511

Source:http://linkedlifedata.com/resource/pubmed/id/10548511

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1999-12-17
pubmed:abstractText
The nitric oxide synthases (NOSs) consist of a flavin-containing reductase domain, linked to a heme-containing oxygenase domain, by a calmodulin (CaM) binding sequence. The flavin-containing reductase domains of the NOS isoforms possess close sequence homology to NADPH-cytochrome P450 reductase (CPR). Additionally, the oxygenase domains catalyze monooxygenation of L-arginine through a cytochrome P450-like cysteine thiolate-liganded heme bound in the active site. With these considerations in mind, we conducted studies in an attempt to gain insight into the intermediates involved in flavoprotein-to-heme electron transfer in the NOSs. Static, steady-state, and stopped-flow kinetic studies indicated that nNOS must be reduced to a more than one-electron-reduced intermediate before efficient electron transfer can occur. Therefore, the possibility exists that the oxygenase domains of the NOS isoforms may receive their electrons from the reductase domains by a mechanism resembling the CPR-P450 interaction. Furthermore, the rate-limiting step in electron transfer appears to be the transfer of electrons from the flavoprotein to the oxygenase domain facilitated by the binding of CaM at increased intracellular Ca(2+) concentrations. Thus, modulation of electron transfer rates appears to be regulated at the level of the flavoprotein domains of the NOS isoforms.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0006-291X
pubmed:author
pubmed:copyrightInfo
Copyright 1999 Academic Press.
pubmed:issnType
Print
pubmed:volume
265
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
184-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Rapid kinetic studies of electron transfer in the three isoforms of nitric oxide synthase.
pubmed:affiliation
Department of Biochemistry, University of Texas Health Science Center at San Antonio, San Antonio, Texas, 78229-3900, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't