Systematic synthetic and biophysical development of mixed sequence DNA binding agents

Area of Science:

• Chemical Biology
• Genomics
• Molecular Biology

Background:

• Most of the human genome, beyond protein-coding regions, has functional roles in RNA synthesis and gene expression control.
• Targeting specific DNA sequences with small molecules offers significant potential for biotechnology and therapeutics.
• Developing compounds that recognize mixed-base pair DNA sequences is crucial for advancing gene targeting strategies.

Purpose of the Study:

• To design and synthesize novel small molecules capable of binding strongly to mixed-base pair DNA sequences.
• To create compounds that can be rationally designed from modular components for specific DNA recognition.
• To explore new classes of DNA-binding agents for potential therapeutic and biotechnological applications.

Main Methods:

• Design and synthesis of small molecules incorporating AT-specific binding modules and linkers for G·C recognition.
• Evaluation of compound-DNA interactions using a comprehensive suite of biophysical methods.
• Characterization of binding affinity (K_D), dissociation kinetics, and sequence selectivity.

Main Results:

• Pyridyl-linked compounds demonstrated sub-nanomolar binding affinity (K_D) to the target DNA sequence.
• These compounds exhibited very slow dissociation kinetics, indicating strong binding.
• A selectivity of 200-fold was observed for the target sequence containing G·C pairs over a related sequence lacking them.
• Compounds with AT modules linked differently showed cooperative dimer recognition of related sequences.

Conclusions:

• Novel small molecules have been successfully designed to recognize specific mixed-base pair DNA sequences with high affinity and selectivity.
• The modular design approach allows for the expansion of this strategy to recognize a wider range of DNA sequences.
• These findings represent a significant advancement in the development of DNA-binding agents for gene regulation, with implications for biotechnology and therapeutics.