Tetrapeptides induce selective recognition for G-quadruplexes when conjugated to a DNA-binding platform.

Area of Science:

• Medicinal Chemistry
• Biochemistry
• Molecular Biology

Background:

• G-quadruplex DNA structures are increasingly recognized as important therapeutic targets.
• Developing selective ligands for G-quadruplex DNA over duplex DNA remains a challenge.

Purpose of the Study:

• To design and synthesize novel acridine and acridone conjugates for selective G-quadruplex DNA interaction.
• To investigate the influence of peptide sequence on ligand binding specificity.
• To elucidate the molecular interactions responsible for G-quadruplex recognition.

Main Methods:

• Synthesis of 3,6-Bis-peptide acridine and acridone conjugates.
• G-quadruplex DNA binding assays to determine specificity.
• Molecular modeling and computational studies to rationalize binding interactions.

Main Results:

• Conjugates demonstrated selective interaction with G-quadruplex DNA.
• The FRHR tetrapeptide conjugate exhibited the highest specificity (>50-fold).
• Molecular modeling revealed tetrapeptide accommodation and stabilization within the quadruplex TTA loop pockets via non-bonded interactions.

Conclusions:

• Peptide sequence is critical for achieving high specificity in G-quadruplex DNA recognition.
• Hybrid molecules targeting distinct G-quadruplex features represent a viable strategy for discriminating between quadruplex and duplex DNA.
• The FRHR-conjugated ligand shows potential for therapeutic applications targeting G-quadruplex structures.