Linked Life Data

10446162

Source:http://linkedlifedata.com/resource/pubmed/id/10446162

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
34
pubmed:dateCreated
1999-9-9
pubmed:abstractText
Benzo[a]pyrene (B[a]P) is a widespread environmental carcinogen that must be activated by cellular metabolism to a diol epoxide form (BPDE) before it reacts with DNA. It has recently been shown that BPDE preferentially modifies the guanine in methylated 5'-CpG-3' sequences in the human p53 gene, providing one explanation for why these sites are mutational hot spots. Using purified duplex oligonucleotides containing identical methylated and unmethylated CpG sequences, we show here that BPDE preferentially modified the guanine in hemimethylated or fully methylated CpG sequences, producing between 3- and 8-fold more modification at this site. Analysis of this reaction using shorter duplex oligonucleotides indicated that it was the level of the (+)-trans isomer that was specifically increased. To determine if there were conformational differences between the methylated and unmethylated B[a]P-modified DNA sequences that may be responsible for this enhanced reactivity, a native polyacrylamide gel electrophoresis analysis was carried out using DNA containing isomerically pure B[a]P-DNA adducts. These experiments showed that each adduct resulted in an altered gel mobility in duplex DNA but that only the presence of a (+)-trans isomer and a methylated C 5' to the adduct resulted in a significant gel mobility shift compared with the unmethylated case.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
23948-55
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Cytosine methylation in a CpG sequence leads to enhanced reactivity with Benzo[a]pyrene diol epoxide that correlates with a conformational change.
pubmed:affiliation
Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.