-transparent.png){kind=logo}
The interaction of chromomycin A3 (an antitumor antibiotic) with right-handed and left-handed polynucleotides has been studied by absorbance, fluorescence, circular dichroism, 31P-NMR and 1H-NMR techniques. Binding to either the B form of poly(dG-dC) or the Z form of poly(dG-m5dC) shifts the absorbance maximum to higher wavelength and enhances the fluorescence of the drug. Circular dichroic spectra of solutions containing various concentrations of chromomycin A3 and fixed concentrations of either B or Z polynucleotides show well defined isoelliptic points at similar wavelengths. At the isoelliptic point, the drug complex with B DNA exhibits positive ellipticity while with Z DNA it exhibits negative ellipticity. 31P-NMR spectra of the chromomycin A3 complex with the Z form of poly(dG-m5dC) demonstrate that the Z conformation is retained in the drug complex up to one molecule drug/four base pairs. At Mg2+ concentrations lower than that necessary to stabilize the left-handed conformation of poly(dG-m5dC) alone, 31P analysis shows that chromomycin A3 can bind simultaneously to both the B and Z conformations of poly(dG-m5dC), with no effect on the B-Z equilibrium. These data demonstrate that chromomycin A3 binds to left-handed poly(dG-m5dC) with retention of the left-handed conformation up to saturating drug concentrations.
R H Shafer, and
B P Roques, and
J B LePecq, and
M Delepierre
June 1986,
Nucleic acids research,
R H Shafer, and
B P Roques, and
J B LePecq, and
M Delepierre
May 1991,
Biochemical and biophysical research communications,
R H Shafer, and
B P Roques, and
J B LePecq, and
M Delepierre
April 1985,
Biological chemistry Hoppe-Seyler,
R H Shafer, and
B P Roques, and
J B LePecq, and
M Delepierre
December 1985,
Biochemistry,
R H Shafer, and
B P Roques, and
J B LePecq, and
M Delepierre
June 1985,
Nucleic acids research,
R H Shafer, and
B P Roques, and
J B LePecq, and
M Delepierre
April 1988,
Biopolymers,
R H Shafer, and
B P Roques, and
J B LePecq, and
M Delepierre
January 1981,
Nature,
R H Shafer, and
B P Roques, and
J B LePecq, and
M Delepierre
June 1993,
International journal of biological macromolecules,
R H Shafer, and
B P Roques, and
J B LePecq, and
M Delepierre
June 1982,
Biochemical and biophysical research communications,
R H Shafer, and
B P Roques, and
J B LePecq, and
M Delepierre
March 1982,
Proceedings of the National Academy of Sciences of the United States of America,
