KcsA-Kv1.x chimeras with complete ligand-binding sites provide improved predictivity for screening selective...

Area of Science:

• Biophysics
• Molecular Biology
• Pharmacology

Background:

• Autoimmune diseases and chronic inflammation present significant unmet therapeutic needs.
• Blocking the Kv1.3 potassium channel is a promising strategy for modulating T cells.
• Developing selective Kv1.3 inhibitors is challenging, necessitating improved screening tools.

Purpose of the Study:

• To design and validate advanced chimeric ion channels for enhanced peptide ligand screening.
• To improve the predictivity of phage display screening for Kv1.3 inhibitors.
• To provide a more reliable tool for drug development targeting Kv1.3 channels.

Main Methods:

• Construction and production of KcsA-Kv1.x chimeric proteins incorporating turret and filter regions (T+F chimeras).
• Phage display-based high-throughput screening using enzyme-linked immunosorbent assays (ELISA).
• Electrophysiological validation of peptide toxin binding and selectivity.

Main Results:

• T+F chimeras demonstrated superior peptide ligand-binding predictivity over T-only chimeras.
• The filter region of KcsA-Kv1.x chimeras is crucial for accurate relative affinity ordering of peptide toxins.
• Screening results correlated well with electrophysiological data, confirming improved reliability.

Conclusions:

• Advanced KcsA-Kv1.x T+F chimeras represent a superior screening tool for Kv1.3 inhibitor development.
• Inclusion of the filter region enhances the accuracy of selectivity profiling for ion channel modulators.
• These findings facilitate future drug discovery efforts for autoimmune and inflammatory diseases.