Spectroscopic Investigation of Emetine-DNA Binding.

Area of Science:

• Molecular Biology
• Biochemistry
• Computational Chemistry

Background:

• Emetine is a natural isoquinoline alkaloid with diverse pharmacological activities.
• Understanding emetine's interaction with DNA is crucial for elucidating its biological mechanisms.

Purpose of the Study:

• To investigate the mode and energetics of emetine-DNA association.
• To characterize the binding interactions using spectroscopic and computational approaches.

Main Methods:

• UV-vis spectroscopy to monitor DNA binding.
• Fourier-transform infrared (FTIR) spectroscopy to analyze molecular interactions.
• Molecular docking simulations to predict binding modes and energies.

Main Results:

• UV-vis spectroscopy showed hypochromic and bathochromic shifts, indicating strong base pair interactions.
• A moderate binding constant (K = 1.10 × 10^6 M^-1) and negative Gibbs free energy (ΔG° = -8.26 kcal·mol^-1) confirmed spontaneous binding.
• FTIR revealed perturbations in guanine and phosphate vibrations, suggesting hydrogen bonding and π-π stacking.
• Docking simulations identified a favorable binding pose of emetine in the DNA minor groove, with hydrogen bonding to guanine.

Conclusions:

• Spectroscopic and computational data support a minor groove binding model for emetine-DNA interactions.
• The study provides a foundation for further high-resolution structural investigations of emetine-DNA complexes.