Background: Controlling the structure of proto-oncogene telomeres is very important in
antitumor therapy. There are relationships between G-quadruplex DNA and the growth of tumor cell.
Methods: In this study, spectroscopic, cyclic voltammetry and viscosity methods were employed to
investigate the interaction between Zn-Arsenazo Ⅲ complex and G-quadruplex DNA by using 4S
Green Plus Nucleic Acid Stain as a spectral probe in PBS buffer. The binding ratios were n Arsenazo Ⅲ
: n Zn(Ⅱ) = 5:1 for Zn-Arsenazo Ⅲ complex and n Zn- Arsenazo Ⅲ : n G-quadruplex DNA = 8:1 for Zn-Arsenazo
Ⅲ-G-quadruplex DNA. The bonding constants (Kθ
298.15K=4.44x105 L·mol-1, Kθ
318.15K= 1.04x106 L·mol-1) were obtained by double reciprocal method at different temperatures, Which was found that the interaction between Zn-Arsenazo Ⅲ complex and Gquadruplex
DNA was driven by enthalpy. Furthermore, the research further confirmed that the interaction
mode between Zn-Arsenazo Ⅲ complex and G-quadruplex DNA was a mixed binding
which involved intercalation and non-intercalation interaction.
Results and Conclusion: Together these findings also have corroborated the application of stabilizing
ligands and intervening with their function for target G-quadruplexes in a cellular context.