Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1989-6-22
pubmed:abstractText
Among the DNA-intercalating drugs in the ellipticinium series, 9-hydroxy derivatives elicit the highest antitumoral properties. In water these drugs display a very low fluorescence quantum yield. Replacement of H2O by D2O partially restores the fluorescence of the ellipticinium chromophore. The possibility that such a proton-exchange mechanism could be involved in a base-recognizing process at the DNA level (and therefore be responsible for some base preference) was examined by direct fluorescence titration in deuterated buffer and DNA/drug fluorescence energy transfer. These experimental approaches provide mutually consistent results showing that the 9-hydroxylated drug recognizes specific DNA sites that are not recognized by the non-hydroxylated drug. When compared to 2-N-methyl ellipticinium, the 2-N-methyl 9-hydroxyellipticinium presents: (1) higher binding constants for each DNA studied; (2) a base dependence of the fluorescence properties of the bound form (fluorescence increment upon DNA binding varying over 5-11); (3) a base dependence of its DNA affinity constants (1.1-3.3 x 10(6) M-1) and of its site size (exclusion parameters varying over 3.0-4.4); (4) a base dependence of its energy transfer from DNA bases. Analysis of the binding data suggests that the 9-hydroxyl group of 2-N-methyl ellipticinium is responsible for a G.C base-pair preference, the preferred binding site being a doublet sequence of two adjacent G.C which could be flanked either by a additional G.C base pair or by an A.T base pair.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
181
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
129-34
pubmed:dateRevised
2007-7-23
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
The G.C base-pair preference of 2-N-methyl 9-hydroxyellipticinium.
pubmed:affiliation
Unité de Biochimie-Enzymologie, UA 147 CNRS, U 140 INSERM, Villejuif, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't