Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1995-2-13
pubmed:abstractText
A Clark-type nitric oxide-sensitive electrode was used for electrochemical determination of NO oxidation kinetics. Reaction with molecular oxygen followed second-order rate law with respect to NO with an overall rate constant of 9.2 +/- 0.33 x 10(6) M-2 s-1. Tetrahydrobiopterin, an essential cofactor of NO synthases, was found to induce rapid oxidation of NO in a 1:1 stoichiometry. The reaction required the presence of oxygen, was zero order with respect to NO and first order with respect to tetrahydrobiopterin, completely blocked by 5,000 units/ml superoxide dismutase, and mimicked by a superoxide-generating system. Purified brain NO synthase produced no detectable NO unless high amounts of superoxide dismutase were present. NO synthase-catalyzed citrulline formation was inhibited by superoxide dismutase (5,000 units/ml) in an oxyhemoglobin-sensitive manner, indicating that NO induces feedback inhibition of NO synthase. NO-stimulated soluble guanylyl cyclase was inhibited by tetrahydrobiopterin at half-maximally active concentrations of 2 microM. The present data suggest that NO is inactivated to peroxynitrite by superoxide generated in the course of tetrahydrobiopterin autoxidation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
13
pubmed:volume
270
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
655-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Kinetics and mechanism of tetrahydrobiopterin-induced oxidation of nitric oxide.
pubmed:affiliation
Institut für Pharmakologie und Toxikologie, Karl-Franzens-Universität Graz, Austria.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't