Rationally Designed Protein-Based Inhibitor of α-Synuclein Fibrillization in Cells

Area of Science:

• Neuroscience
• Biochemistry
• Drug Discovery

Background:

• Misfolding of alpha-synuclein (αSyn) into amyloid fibrils is a central pathological hallmark of Parkinson's disease (PD).
• Inhibiting αSyn fibril formation is a key therapeutic strategy for PD treatment.
• Recent structural data on αSyn fibrils provides a basis for designing targeted inhibitors.

Purpose of the Study:

• To engineer protein inhibitors with high affinity for αSyn fibrils.
• To evaluate the efficacy of these inhibitors in preventing fibril elongation and aggregation.
• To assess the potential of these inhibitors as a therapeutic approach for Parkinson's disease.

Main Methods:

• Protein engineering based on αSyn fibril structural data.
• Affinity-based binding assays to αSyn fibrils.
• Cell-based assays to evaluate inhibitor efficacy (IC50 determination).
• Assessment of inhibitor toxicity and cellular activity.

Main Results:

• Engineered inhibitors demonstrate higher affinity for αSyn fibrils compared to monomeric αSyn.
• Inhibitors effectively bind to fibril ends, preventing further elongation.
• The best inhibitor exhibits an IC50 of approximately 10 nM in cell-based assays.
• Inhibitors are selective for misfolded αSyn, non-toxic, and active at low concentrations in the cytosol.

Conclusions:

• Developed protein inhibitors show high efficacy in preventing αSyn fibril formation and elongation.
• These inhibitors are selective, non-toxic, and effective at low concentrations.
• The findings suggest potential for these inhibitors to slow the cell-to-cell spread of pathological αSyn aggregates in Parkinson's disease.