Enzyme-Mimic Peptide Assembly To Achieve Amidolytic Activity

Area of Science:

• Biomaterials Science
• Catalysis
• Nanotechnology

Background:

• Amyloid fibers are versatile bionanomaterials with tunable properties.
• Enzyme-mimic approaches are key to developing artificial catalysts.
• Peptide self-assembly offers a route to novel functional materials.

Purpose of the Study:

• To design and synthesize peptide catalysts (PCs) that self-assemble into amyloid-like fibrils.
• To investigate the structural characteristics and catalytic amidolytic activity of these fibrillar peptides.
• To explore the influence of pH and temperature on fibril formation and activity.

Main Methods:

• Enzyme-mimic approach to incorporate catalytic residues into peptides.
• Rational design of amino acid sequences for self-assembly.
• Characterization using atomic force microscopy, Raman spectroscopy, and wide-angle X-ray scattering.
• Validation of amidolytic activity through inhibition assays.

Main Results:

• Peptides successfully self-assembled into amyloid-like fibrils with distinct morphologies controlled by pH and temperature.
• Fibril structure and stability were correlated with amidolytic activity.
• One peptide catalyst (PC4) demonstrated enzyme-like amidolytic catalysis.
• Fibrillation pH critically impacts catalytic triad pKa and fibril stability.

Conclusions:

• Designed peptides can self-assemble into functional amyloid fibrils capable of enzyme-like catalysis.
• Tunable bionanomaterials like amyloid fibrils hold potential for creating efficient artificial enzymes.
• Controlling fibril morphology and stability is crucial for optimizing catalytic performance.