Small Molecule Sequestration of the Intrinsically Disordered Protein, p27^Kip1, Within Soluble Oligomers

Area of Science:

• Biochemistry
• Molecular Biology
• Drug Discovery

Background:

• Intrinsically disordered proteins (IDPs) are crucial for cellular functions like signaling and regulation.
• Misregulation of IDPs is linked to diseases such as cancer and neurodegeneration.
• The flexibility of IDPs challenges traditional structure-based drug design, labeling them 'undruggable'.

Purpose of the Study:

• To develop novel therapeutic strategies for targeting intrinsically disordered proteins (IDPs).
• To design and synthesize analogs of previously identified small molecules with enhanced affinity for the p27 protein.
• To investigate the effect of these novel compounds on the structural behavior of p27.

Main Methods:

• Utilized synthetic chemistry for analog development.
• Employed Nuclear Magnetic Resonance (NMR) spectroscopy to study molecular interactions.
• Applied biophysical methods, including analytical ultracentrifugation, to assess binding affinity and structural changes.

Main Results:

• Discovered elaborated analogs with a 30-fold increase in binding affinity for p27 (apparent Kd = 57 ± 19 μM).
• Observed that high-affinity compounds induced the formation of soluble, disordered oligomers of p27.
• Demonstrated specific binding to dynamic aromatic clusters within the intrinsically disordered protein p27.

Conclusions:

• The developed analogs show significantly improved affinity for the intrinsically disordered protein p27.
• The formation of soluble disordered oligomers by high-affinity compounds suggests a novel mechanism of action.
• Propose oligomer sequestration as a potential therapeutic strategy for targeting disease-associated IDPs.