Linked Life Data

9649322

Source:http://linkedlifedata.com/resource/pubmed/id/9649322

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
26
pubmed:dateCreated
1998-7-23
pubmed:abstractText
The effects of eleven camptothecin derivatives on calf thymus topoisomerase I-mediated cleavage of synthetic DNA duplex have revealed that the A ring of camptothecin is very important for its biochemical activity. Depending on the type, number, and location of substituents, highly active or inactive analogues were obtained. The persistence of CPT-induced topoisomerase I-DNA covalent binary complexes was investigated by using as substrates DNA containing several good topoisomerase I cleavage sites, or else a synthetic DNA duplex of defined structure with a single high-efficiency cleavage site. The ligation kinetics at a given topoisomerase I cleavage site were sometimes quite different in the presence of CPT derivatives whose structures were closely related. Even in the presence of a single CPT analogue, topoisomerase I-DNA covalent binary complexes underwent ligation with different kinetics, presumably reflecting a dependence on DNA sequences flanking the individual topoisomerase I cleavage sites. Individual camptothecin derivatives also exhibited a spectrum of inhibitory potentials in blocking the topoisomerase I-mediated rearrangement of branched, nicked, and gapped DNA duplex substrates; in some cases the potencies of inhibition observed in these assays for individual camptothecin analogues were quite different than those determined for stabilization of the unmodified DNA-topoisomerase I binary complex.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
37
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9399-408
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Differential effects of camptothecin derivatives on topoisomerase I-mediated DNA structure modification.
pubmed:affiliation
Department of Chemistry, University of Virginia, Charlottesville 22901, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.