Non-specific yet selective interactions contribute to small molecule condensate partitioning behavior

Area of Science:

• Biochemistry and Molecular Biology
• Computational Biology
• Drug Discovery

Background:

• Biomolecular condensates are crucial for cellular functions.
• Dysregulation of condensates is linked to various diseases.
• Understanding small molecule interactions with condensates is key for therapeutic development.

Purpose of the Study:

• To investigate the mechanistic basis of small molecule interactions with biomolecular condensates.
• To characterize the chemical environments within condensates that bind small molecules.
• To provide insights for the rational design of therapeutics targeting specific condensates.

Main Methods:

• Utilized a multiscale approach for long-time, equilibrated all-atom simulations.
• Systematically characterized ligand binding poses within diverse condensate systems.
• Analyzed amino acid composition and physicochemical properties of binding environments.

Main Results:

• Biomolecular condensates present heterogeneous chemical environments for small molecule binding.
• Interactions are primarily driven by non-specific hydrophobic forces, differing from traditional protein-ligand interactions.
• Condensate-specific amino acid compositions and population shifts dictate ligand selectivity and partitioning.

Conclusions:

• The study elucidates the complex, non-specific binding mechanisms of small molecules within biomolecular condensates.
• Findings enhance the interpretation of experimental screening data for condensate-targeting drugs.
• The developed approach aids in the rational design of small molecules for specific condensate modulation.