Interaction of mithramycin with DNA. Evidence that mithramycin binds to DNA as a dimer in a right-handed screw conformation.
Eur J Biochem
; 198(2): 333-8, 1991 Jun 01.
Article
em En
| MEDLINE
| ID: mdl-1828228
ABSTRACT
The CD and fluorescence properties of mithramycin have been used to follow its complexation to cations such as Mg2+ and Zn2+ and the binding of these complexes to DNA. At low concentration (less than 2 microM) in aqueous solution, mithramycin is always in the dimeric state, the conformation of the dimer being either a right-handed screw when the dimer is neutral, or a left-handed screw when the dimer is negatively charged. In the deprotonated state the dimer can bind one cation forming a complex [M2+(Mit-)2] which has a right-handed screw conformation. The stability constants of the complex at 37 degrees C in 0.1 M KCl are 4 x 10(5) and 1 x 10(6) for Mg2+ and Zn2+, respectively. The complex in the right-handed screw conformation binds DNA. In this case the stability constants of the complex [M2+ (Mit-)2] increase and are 3.6 x 10(6) and 1.2 x 10(7) for Mg2+ and Zn2+, respectively.
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Base de dados:
MEDLINE
Assunto principal:
DNA
/
Plicamicina
Idioma:
En
Ano de publicação:
1991
Tipo de documento:
Article