Switch to
Predicate | Object |
---|---|
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 |
http://linkedlifedata.com/resource/pubmed/chemical/5,6,7,8-tetrahydrobiopterin,
http://linkedlifedata.com/resource/pubmed/chemical/Amino Acid Oxidoreductases,
http://linkedlifedata.com/resource/pubmed/chemical/Biopterin,
http://linkedlifedata.com/resource/pubmed/chemical/Nitric Oxide,
http://linkedlifedata.com/resource/pubmed/chemical/Nitric Oxide Synthase,
http://linkedlifedata.com/resource/pubmed/chemical/Superoxide Dismutase
|
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-meshheading:7529763-Amino Acid Oxidoreductases,
pubmed-meshheading:7529763-Animals,
pubmed-meshheading:7529763-Biopterin,
pubmed-meshheading:7529763-Cattle,
pubmed-meshheading:7529763-Kinetics,
pubmed-meshheading:7529763-Nitric Oxide,
pubmed-meshheading:7529763-Nitric Oxide Synthase,
pubmed-meshheading:7529763-Oxidation-Reduction,
pubmed-meshheading:7529763-Superoxide Dismutase,
pubmed-meshheading:7529763-Swine
|
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
|