SPECIFIC-INHIBITION OF FORMATION OF TRANSCRIPTION COMPLEXES BY A CALICHEAMICIN OLIGOSACCHARIDE - A PARADIGM FOR THE DEVELOPMENT OF TRANSCRIPTIONAL ANTAGONISTS
Sn. Ho et al., SPECIFIC-INHIBITION OF FORMATION OF TRANSCRIPTION COMPLEXES BY A CALICHEAMICIN OLIGOSACCHARIDE - A PARADIGM FOR THE DEVELOPMENT OF TRANSCRIPTIONAL ANTAGONISTS, Proceedings of the National Academy of Sciences of the United Statesof America, 91(20), 1994, pp. 9203-9207
Sequence-specific DNA ligands that antagonize DNA-protein interactions
represent a potentially powerful means of modulating gene expression.
Calicheamicin gamma 1(I), a member of the DNA-cleaving enediyne class
of anticancer antibiotics, binds to specific DNA sequences through an
aryltetrasaccharide domain. To take advantage of this unique sequence
-specific recognition capability, the methyl glycoside of the aryltetr
asaccharide of calicheamicin gamma 1(I) (CLM-MG) was used to investiga
te the ability of glycoconjugate DNA ligands to inhibit DNA-protein in
teractions. CLM-MG inhibits the formation of DNA-protein complexes at
micromolar concentrations in a sequence-specific manner and rapidly di
ssociates preformed complexes. CLM-MG also inhibits transcription in v
ivo with similar sequence specificity. These results suggest a strateg
y for the development of a class of novel biological probes and therap
eutic agents.