Source:http://linkedlifedata.com/resource/pubmed/id/15813901
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
4
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| pubmed:dateCreated |
2005-4-7
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| pubmed:abstractText |
Melatonin, a derivative of the essential amino acid tryptophan, has been portrayed as a hormone, a tissue factor, an autocoid, a paracoid, and a vitamin with antioxidative capabilities. In the present study a novel reaction which cannot be attributed to any of these suggested features, i.e. the transfer of the nitroso-function from N-nitrosotryptophan derivatives to melatonin, is unequivocally demonstrated. In the lipophilic buffer dimethylsulfoxide reaction of N-acetyl-N-nitrosotryptophan (NANT) with melatonin was very slow (k = 1.5 x 10(-6)/m/s), but reversible as shown by 15N-NMR spectrometry. These measurements demonstrated also that the thermodynamical equilibrium lies on the side of N-nitrosomelatonin (NOMela). Quantum-chemical calculations performed with the third-generation density functional B97-2 additionally predicted that this is also the case in an aqueous environment. In fact, reaction of melatonin with either NANT or N-nitrosotryptophan located at the endothelin-1 fragment 16-21 yielded NOMela with a rate constant of 1.7 +/- 0.5/m/s as shown by capillary zone electrophoresis. Interestingly, the known reactive nitrogen oxide species scavenger, piperazine, did not inhibit the NANT-dependent nitrosation of melatonin, thus very strongly indicating a direct transnitrosation reaction. All of these capabilities are known from the reaction of S-nitrosothiols with thiolate anions and are believed to be highly important in the transport and targeting of nitric oxide.
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:citationSubset |
IM
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| pubmed:chemical | |
| pubmed:status |
MEDLINE
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| pubmed:month |
May
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| pubmed:issn |
0742-3098
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:volume |
38
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
247-53
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| pubmed:meshHeading | |
| pubmed:year |
2005
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| pubmed:articleTitle |
First insights into regiospecific transnitrosation reactions between tryptophan derivatives: melatonin as an effective target.
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| pubmed:affiliation |
Institut für Physiologische Chemie, Universitätsklinikum Essen, Essen, Germany. michael.kirch@uni-essen.de
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| pubmed:publicationType |
Journal Article
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