Complex Biophysical and Computational Analyses of G-Quadruplex Ligands: The Porphyrin Stacks Back

Area of Science:

• Molecular Biology
• Material Science
• Supramolecular Chemistry

Background:

• G-quadruplexes (G4s) are non-canonical DNA structures with significant implications in gene regulation and telomere maintenance.
• Small molecules targeting G4s are crucial for modulating these biological processes.
• Meso-tetrakis-(N-methyl-4-pyridyl) porphyrin (TMPyP4) is a widely used G4 ligand.

Purpose of the Study:

• To synthesize and characterize novel tetracationic porphyrin derivatives as G4 ligands.
• To investigate the binding and stabilizing capacity of these derivatives against various DNA sequences.
• To evaluate the selectivity of these new ligands for different G4 structures.

Main Methods:

• Molecular docking and dynamics simulations.
• Chemical synthesis of tetracationic porphyrin derivatives.
• Spectroscopic and spectrometric analyses (e.g., UV-Vis, fluorescence, NMR).

Main Results:

• Successfully synthesized novel tetracationic porphyrin derivatives.
• Demonstrated binding and stabilization of G-quadruplex structures by the synthesized compounds.
• Identified that peripheral amide groups enhance selectivity for parallel G4s over other DNA structures.

Conclusions:

• Tetracationic porphyrin derivatives exhibit potent G4 binding and stabilization capabilities.
• The presence of amide groups confers selectivity for parallel G4s.
• 5,10,15,20-tetrakis-(1-acetamido-4-pyridyl) porphyrin bromide is a promising, easily synthesized alternative to TMPyP4 for G4 binding studies.