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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
21
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pubmed:dateCreated |
1992-11-18
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pubmed:abstractText |
Chloroethylnitrosoureas induce reactive O6-guanine adducts in DNA that can form either interstrand cross-links or a covalent complex with the DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT). To test our hypothesis that these end-products are formed from the common precursor, 1-O6-ethanoguanine, we compared the kinetics of interstrand cross-link formation with those of decay of MGMT complex forming capacity. The half-lives of these processes were identical. Our hypothesis also predicts that the linkage between DNA and MGMT is 1-(guan-1-yl)-2-(cystein-S-yl)ethane. This notion was tested by forming the complex with 35S-labeled recombinant human MGMT and a chloroethylnitrosourea-treated oligodeoxynucleotide. After degradation by depurination and proteolytic digestion, the identity of the [35S]cysteine-guanine linkage was confirmed by comparison with the synthetic marker compound using high performance liquid chromatography and UV spectrometry. These results strengthen the hypothesis that DNA interstrand cross-links and DNA-MGMT complex both arise from the same precursor. The data also suggest that 1-O6-ethanoguanine is a good substrate for MGMT such that, under certain conditions in vivo, DNA-MGMT complex formation may constitute a significant secondary lesion.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/1-(2-chloroethyl)-1-nitrosourea,
http://linkedlifedata.com/resource/pubmed/chemical/Antineoplastic Agents,
http://linkedlifedata.com/resource/pubmed/chemical/DNA,
http://linkedlifedata.com/resource/pubmed/chemical/Ethylnitrosourea,
http://linkedlifedata.com/resource/pubmed/chemical/Guanine,
http://linkedlifedata.com/resource/pubmed/chemical/Methyltransferases,
http://linkedlifedata.com/resource/pubmed/chemical/O(6)-Methylguanine-DNA...
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pubmed:status |
MEDLINE
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pubmed:month |
Nov
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pubmed:issn |
0008-5472
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
1
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pubmed:volume |
52
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
6052-8
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:1394230-Antineoplastic Agents,
pubmed-meshheading:1394230-Base Sequence,
pubmed-meshheading:1394230-Chromatography, High Pressure Liquid,
pubmed-meshheading:1394230-DNA,
pubmed-meshheading:1394230-Electrophoresis, Polyacrylamide Gel,
pubmed-meshheading:1394230-Ethylnitrosourea,
pubmed-meshheading:1394230-Guanine,
pubmed-meshheading:1394230-Humans,
pubmed-meshheading:1394230-Kinetics,
pubmed-meshheading:1394230-Methyltransferases,
pubmed-meshheading:1394230-Molecular Sequence Data,
pubmed-meshheading:1394230-O(6)-Methylguanine-DNA Methyltransferase
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pubmed:year |
1992
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pubmed:articleTitle |
Identification of the cross-link between human O6-methylguanine-DNA methyltransferase and chloroethylnitrosourea-treated DNA.
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pubmed:affiliation |
Department of Biochemical and Clinical Pharmacology, St. Jude Children's Research Hospital, Memphis, Tennessee 38101.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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