Thermodynamics of the interactions of m-AMSA and o-AMSA with nucleic acids: influence of ionic strength and DNA base composition.
AUTOR(ES)
Wadkins, R M
RESUMO
The equilibrium binding of the antitumor agent m-AMSA and its biologically inactive analog o-AMSA to native and synthetic DNAs are compared over a wide range of ionic strengths and temperatures. Although o-AMSA binds DNA with a higher affinity than m-AMSA it is not effective as an antitumor agent. Both m-AMSA and o-AMSA bind DNA in an intercalative manner. Indepth investigations into the thermodynamic parameters of these interactions reveal the interaction of m-AMSA with DNA to be an enthalpy driven process. In contrast, the structurally similar but biologically inactive o-AMSA binds DNA through an entropy driven process. The differences in thermodynamic mechanisms of binding between the two isomers reveal that the electronic and/or steric factors resulting from the position of the methoxy substituent group on the anilino ring directs the DNA binding properties of these compounds and ultimately the biological effectiveness as an antitumor agent.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=335223Documentos Relacionados
- Cooperative binding of m-AMSA to nucleic acids.
- Interaction of the antitumour drug 4'-(9-acridinylamino)-methanesulfon-m-anisidine.HCl (m-AMSA) with nucleic acids.
- Theoretical calculations of base-base interactions in nucleic acids: II. Stacking interactions in polynucleotides.
- Energetics and stereochemistry of DNA complexation with the antitumor AT specific intercalators tilorone and m-AMSA.
- Theoretical calculations of base-base interactions in nucleic acids: I. Stacking interactions in free bases.