Targeting S100 Calcium-Binding Proteins with Small Molecule Inhibitors

Area of Science:

• Biochemistry
• Molecular Biology
• Drug Discovery

Background:

• S100B is a calcium-binding protein implicated in cancer, driving interest in therapeutic inhibitors.
• Developing selective S100B inhibitors is crucial for cancer treatment, necessitating efficient screening methods.

Purpose of the Study:

• To describe two fluorescence polarization competition assays (FPCAs) for high-throughput screening (HTS) of S100B and S100A1.
• To enable the identification and characterization of S100B inhibitors with therapeutic potential.
• To develop a counter-screen assay for S100A1 to ensure inhibitor selectivity.

Main Methods:

• Development of two FPCAs for S100B and S100A1.
• Utilizing FPCAs for high-throughput screening (HTS) to determine inhibitor binding affinity (K_i).
• Establishing methods for recombinant protein expression and purification of S100B and S100A1 for HTS.

Main Results:

• Successfully established two FPCAs suitable for HTS campaigns.
• Demonstrated the utility of the assays in identifying and characterizing S100B inhibitors.
• Developed a counter-screen to exclude compounds inhibiting S100A1.

Conclusions:

• The described FPCAs are effective tools for identifying selective S100B inhibitors.
• These assays facilitate the discovery of novel therapeutics targeting S100B in diseases like cancer.
• The methods support large-scale screening efforts for drug development.