A redox cycle meets insulin fibrillation in vitro

Area of Science:

• Biochemistry
• Molecular Biology
• Drug Discovery

Background:

• Amyloid protein misfolding and fibrillation are implicated in various diseases, with limited effective treatments available.
• Insulin fibrillation serves as a key model for studying amyloidogenesis.
• Developing novel inhibitors of protein fibrillation is crucial for therapeutic intervention.

Purpose of the Study:

• To investigate the effect of resazurin and resorufin on insulin fibrillation.
• To elucidate the mechanism by which resazurin modulates insulin fibrillation.
• To assess the potential of resazurin as a therapeutic agent against amyloidosis.

Main Methods:

• Biochemical assays to monitor fibrillation kinetics.
• Spectroscopic techniques (e.g., fluorescence, circular dichroism) to analyze protein structure.
• Imaging tools (e.g., microscopy) to visualize fibril formation.
• Investigated electrostatic interactions between insulin and resazurin at low pH.

Main Results:

• Resazurin significantly inhibited insulin fibrillation, while its counterpart resorufin did not.
• Evidence suggests electrostatic interaction between negatively charged resazurin and positively charged insulin at low pH underlies the inhibition.
• Inhibition was effective at various stages of the fibrillation process.
• Resazurin demonstrated potential in eliminating the toxicity associated with protein fibrils.

Conclusions:

• Resazurin is a novel modulator of insulin fibrillation, offering a new avenue for therapeutic development.
• The mechanism involves electrostatic interactions, highlighting the importance of molecular charge in modulating amyloid formation.
• Resazurin's ability to inhibit fibrillation across different stages suggests broad applicability in combating amyloid diseases.
• This biocompatible dye presents a promising, non-toxic approach to mitigate the effects of amyloid protein aggregation.