Small-Molecule 3D Ligand for RNA Recognition: Tuning Selectivity through Scaffold Hopping

Area of Science:

• Medicinal Chemistry
• Molecular Biology
• Drug Discovery

Background:

• Targeting RNA with small molecules is a key area in drug discovery.
• Developing selective RNA ligands requires targeting low-complexity RNA structural motifs.
• Existing promiscuous nucleic acid binders need improved selectivity for therapeutic applications.

Purpose of the Study:

• To investigate shape modification of small molecules as a strategy for designing selective RNA ligands.
• To develop novel compounds with high affinity and selectivity for specific RNA structures.
• To explore the impact of scaffold hopping on RNA/small-molecule interactions.

Main Methods:

• Chemical synthesis of a novel cyanine derivative by replacing a phenyl ring with a [2.2]paracyclophane moiety.
• Evaluation of the compound's binding affinity and selectivity against various nucleic acids.
• Assessment of the compound's behavior within cells (in cellulo).

Main Results:

• The modified cyanine compound demonstrated marked affinity and selectivity for an octahairpin loop RNA sequence.
• The shape modification enabled discrimination between nucleic acids with different structural characteristics.
• The altered molecular shape influenced the compound's in cellulo activity.

Conclusions:

• Tuning the three-dimensional shape of promiscuous nucleic acid binders is an effective strategy for creating selective RNA ligands.
• Scaffold hopping can significantly enhance the selectivity of RNA/small-molecule interactions.
• Exploring novel chemical spaces is crucial for the advancement of selective RNA-targeting drugs.