Interactions of daidzin with intramolecular G-quadruplex

Area of Science:

• Biochemistry
• Molecular Biology
• Medicinal Chemistry

Background:

• Soy isoflavones, like daidzin, are plant-derived compounds with potential health benefits.
• Telomeric G-quadruplexes are unique DNA structures implicated in cancer progression.
• Inhibition of telomerase activity is a key strategy in cancer therapy.

Purpose of the Study:

• To investigate the interaction between daidzin and human telomeric G-quadruplex DNA (dAG(3)(T(2)AG(3))(3)).
• To elucidate the binding stoichiometry and structural changes upon complex formation.
• To explore the potential of daidzin as an anticancer agent targeting telomerase.

Main Methods:

• Electrospray ionization mass spectrometry (ESI-MS)
• Polyacrylamide gel electrophoresis (PAGE)
• Circular dichroism (CD) spectroscopy
• Molecular simulation and computational modeling

Main Results:

• Daidzin forms DNA-daidzin complexes with stoichiometric ratios of 1:1 and 1:2.
• The transition temperature of the G-quadruplex increases with higher daidzin concentrations.
• Interactions are significantly strengthened under molecular crowding conditions.
• The 1:1 complex is stabilized by pi-pi conjugation and hydrogen bonding between daidzin and G-quadruplex bases.

Conclusions:

• Daidzin interacts with telomeric G-quadruplex DNA, forming stable complexes.
• The binding mechanism involves specific molecular interactions.
• Daidzin shows promise as a natural product for developing anticancer therapies by inhibiting telomerase.