On the interaction of doxorubicin with polynucleotides

The interaction of doxorubicin (DX) with model polynucleotides poly(dG-dC)·poly(dG-dC) (polyGC), poly(dA-dT)·poly(dA-dT) (poly-AT), and calf thymus DNA has been studied by several spectroscopic techniques in phosphate buffer aqueous solutions. UV−vis, circular dichroism, and fluorescence spectroscopic data confirm that intercalation is the prevailing mode of interaction, and also reveal that the interaction with AT-rich regions leads to the transfer of excitation energy to DX not previously documented in the literature. Moreover, the DX affinity for AT sites has been found to be on the same order of magnitude as that reported for GC sites.

Effect of alkaline cations on the stability of the model polynucleotide poly(dG-dC).poly(dG-dC).

Interactions of the alternating double stranded copolymer poly(dA-dT).poly(dA-dT) with NiCl2 and CdCl2: solution behaviour

The thermal denaturation of the synthetic high molecular weight double stranded polynucleotide poly(dA-dT) x poly(dA-dT) has been studied in aqueous buffered solution (Tris 1.0 mM; pH 7.8+/-0.2) in the presence of increasing concentrations of either Ni(2+) (borderline cation) or Cd(2+) (soft cation) at four different constant ionic strength values (NaCl), making use of UV and circular dichroism (CD) spectroscopies. The experimental results show that the B-type double helix of the polymer is stabilized against thermal denaturation in the presence of both cations at low concentrations, relative to the systems where only NaCl is present, in the same conditions of ionic strength and pH. The eff…

Circular dichroism of polynucleotides. Interactions of NiCl2 with poly(dA-dT).poly(dA-dT) and poly(dG-dC).poly(dG-dC): solution vs microemulsion behaviour.

Effect of cadmium ions on poly(dA-dT) in cationic microemulsion

Polynucleotides solubilised in a water-in-oil microemulsion: the case of poly(dG-dC). poly(dG-dC)