Linked Life Data

10328757

Source:http://linkedlifedata.com/resource/pubmed/id/10328757

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1999-7-27
pubmed:abstractText
8-Oxoguanine (8-oxo-G) is one of the most common DNA lesions present in normal tissues due to exposure to reactive oxygen species. Studies at this and other laboratories suggest that 8-oxo-G is highly susceptible to secondary oxidation, making it a likely target for endogenous oxidizing agents, such as peroxynitrite (ONOO-). Synthetic oligonucleotides containing 8-oxoguanine were treated with ONOO-, and the reaction products were analyzed by liquid chromatography/electrospray ionization mass spectrometry (LC/ESI--MS). CCACAACXCAAA, CCAAAGGXAGCAG, CCAAAXGGAGCAG, and TCCCGAGCGGCCAAAGGXAGCAG (X is 8-oxo-G) were found to readily react with peroxynitrite via the same transformations as those observed for free 8-oxo-2'-deoxyguanosine. The composition of the reaction mixtures was a function of ONOO- concentration and of the storage time after exposure. The oligonucleotide products isolated at low [ONOO-]/[DNA] ratios (<5) were tentatively assigned as containing 3a-hydroxy-5-imino-3,3a,4,5-tetrahydro-1H-imidazo[4, 5d]imidazol-2-one, 5-iminoimidazolidine-2,4-dione, and its hydrolytic product, oxaluric acid. At a [ONOO-]/[DNA] ratio of >10, 2,4,6-trioxo[1,3,5]triazinane-1-carboxamidine- and cyanuric acid-containing oligomers were the major products. The exact location of a modified base within a DNA sequence was determined using exonuclease digestion of oligonucleotide products followed by LC/ESI--MS analysis of the fragments. For all 8-oxo-G-containing oligomers, independent of the sequence, the reactions with ONOO- took place at the 8-oxo-G residues. These results suggest that 8-oxo-G, if present in DNA, is rapidly oxidized by peroxynitrite and that oxaluric acid is a likely secondary oxidation product of 8-oxo-G under physiological conditions.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0893-228X
pubmed:author
pubmed:issnType
Print
pubmed:volume
12
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
459-66
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Peroxynitrite-induced reactions of synthetic oligonucleotides containing 8-oxoguanine.
pubmed:affiliation
Division of Bioengineering and Environmental Health and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.