Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1995-4-10
pubmed:abstractText
The sequence specificity of topoisomerase-II-mediated DNA cleavage, stimulated by 2-methyl-9-hydroxy ellipticinium and 4',5,7-trihydroxyflavone (genistein) was investigated by sequencing analysis of DNA cleavage sites and molecular modeling techniques. The former drug exhibits a marked preference for a T base at the position immediately preceding the cleavage site (-1). The latter shares the preference for the same base, with an additional preference for a thymine at position +1. The cleavage intensity patterns in the presence of the two drugs differ considerably. From a conformational point of view, ellipticinium and genistein exhibit similar overall shape and dimensions. However, the fused ring system in the former generates a planar structure whereas the single bond, connecting the two aromatic portions in the latter, allows internal rotation. The most stable conformation of genistein corresponds to a deviation of about 40 degrees from planarity. A computer-assisted analysis was carried out to compare the steric and electrostatic properties of the two compounds. Two types of preferred (energetically almost degenerate) alignment for the two molecules were found. One corresponds to overlapping of the 9-hydroxyl containing ring of ellipticinium with the 4'-hydroxyphenyl moiety of genistein, the other envisages the same moiety of ellipticine superimposed to the hydroxyl-benzopyrone portion of genistein. The structural similarities of the test drugs might account for the common preference for stimulation of DNA cleavage at position +1, whereas the different possible arrangements of genistein in the cleavable complex could explain both the additional +1 specificity exhibited by this compound and the differences in cleavage intensity patterns observed in comparison to ellipticinium.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0952-3499
pubmed:author
pubmed:issnType
Print
pubmed:volume
7
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
227-31
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Conformational properties of topoisomerase II inhibitors and sequence specificity of DNA cleavage.
pubmed:affiliation
Department of Pharmaceutical Sciences, University of Padova, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't