Linked Life Data

16843831

Source:http://linkedlifedata.com/resource/pubmed/id/16843831

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2006-7-17
pubmed:abstractText
The reduction of manganese(III) meso-tetrakis((N-ethyl)pyridinium-2-yl)porphyrin (MnTE-2-PyP) to manganese(II) was catalyzed by flavoenzymes such as xanthine oxidase and glucose oxidase, and by Complex I and Complex II of the mitochondrial electron transport chain. The reduced manganese porphyrin has been previously shown to react rapidly with superoxide and carbonate radical anion. Herein, we describe the reaction of a reduced manganese porphyrin with peroxynitrite that proceeds as a two-electron process, has a rate constant greater than 7 x 10(6) M(-1) s(-1) (at pH 7.25 and 37 degrees C), and produces nitrite and the Mn(IV)Porphyrin. The Mn(II)/Mn(IV) redox cycle was used to divert peroxynitrite from the inactivation of succinate dehydrogenase. In a typical experiment, 5 microM MnTE-2-PyP in the presence of excess succinate was able to protect the succinate dehydrogenase and succinate oxidase activities of submitochondrial particles challenged with a cumulative dose of 140 microM peroxynitrite infused in the course of 2 h. Other MnPorphyrins that are reduced more slowly do not provide as much protection underscoring the rate limiting character of the reduction step. The data presented here serve to rationalize the pharmacological action of MnPorphyrins as peroxynitrite reduction catalysts in vivo and opens avenues for the development of MnPorphyrins to protect mitochondria from oxidative damage.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0891-5849
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
41
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
503-12
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Reduction of manganese porphyrins by flavoenzymes and submitochondrial particles: a catalytic cycle for the reduction of peroxynitrite.
pubmed:affiliation
Laboratorio de Fisicoquímica Biológica, Facultad de Ciencias, Universidad de la República, Montevideo 11400, Uruguay.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't