Switch to
Predicate | Object |
---|---|
rdf:type | |
lifeskim:mentions | |
pubmed:issue |
9
|
pubmed:dateCreated |
1983-7-8
|
pubmed:abstractText |
The reaction of 2-thioriboflavin (sulfur replacing the oxygen substituent at position 2 alpha) with hydrogen peroxide at pH approximately 10 leads to a blue flavin (lambda max = 565 nm) which was purified in stable, homogeneous form. Titrations of 2-thioflavins with m-chloroperoxybenzoic acid also yield the same blue flavins with consumption of 1 eq of peracid. Anaerobic reduction of the blue flavin by sodium dithionite requires 4e- eq, and leads to formation of 1,5-dihydro-2-thioflavin. Oxidation of the latter with O2 restores the original 2-thioflavin. pH titration of the blue flavin shows two pKa values of 2.4 and 6.6, with no apparent ionization in the pH range 8-11. These results suggest that the blue flavin is a flavin 2-S-oxide. The visible absorption spectra of flavin 2-S-oxides show a pronounced dependence on solvent polarity. This property suggests that these flavin analogs may be useful hydrophilic/hydrophobic probes of flavoprotein active sites. Flavin 2-S-oxides can be oxidized further to the 2-sulfinate and 2-sulfonate analogs, some properties of which are described.
|
pubmed:grant | |
pubmed:language |
eng
|
pubmed:journal | |
pubmed:citationSubset |
IM
|
pubmed:chemical | |
pubmed:status |
MEDLINE
|
pubmed:month |
May
|
pubmed:issn |
0021-9258
|
pubmed:author | |
pubmed:issnType |
Print
|
pubmed:day |
10
|
pubmed:volume |
258
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
5440-8
|
pubmed:dateRevised |
2007-11-14
|
pubmed:meshHeading |
pubmed-meshheading:6853526-Chromatography, High Pressure Liquid,
pubmed-meshheading:6853526-Chromatography, Thin Layer,
pubmed-meshheading:6853526-Dithionite,
pubmed-meshheading:6853526-Flavins,
pubmed-meshheading:6853526-Flavoproteins,
pubmed-meshheading:6853526-Oxidation-Reduction,
pubmed-meshheading:6853526-Peroxides,
pubmed-meshheading:6853526-Spectrophotometry
|
pubmed:year |
1983
|
pubmed:articleTitle |
Oxidation of 2-thioflavins by peroxides. Formation of flavin 2-S-oxides.
|
pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
|