Tuning of peptide assembly through force balance adjustment

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Biotechnology

Background:

• Amphiphilic tripeptides can self-assemble into ordered nanostructures.
• Controlling molecular architecture is key to directing self-assembly.
• Understanding the forces governing peptide self-assembly is crucial for designing novel nanomaterials.

Purpose of the Study:

• To investigate how subtle molecular modifications in amphiphilic tripeptides affect their self-assembly behavior.
• To explore the role of aromatic interactions and hydrogen bonding in directing nanostructure formation.
• To achieve controlled self-assembly of tripeptides into distinct nanostructures.

Main Methods:

• Synthesis of amphiphilic tripeptides with varying phenylalanine and tyrosine residues.
• Characterization of self-assembled nanostructures using techniques like electron microscopy (implied).
• Analysis of intermolecular forces including hydrogen bonding and π-π stacking.

Main Results:

• Ac-Phe-Phe-Lys-CONH2 (FFK) forms amyloid-like tubular structures driven by β-sheet hydrogen bonding and π-π stacking.
• Substitution of phenylalanine (F) with tyrosine (Y) significantly alters self-assembly.
• FYK and YFK form thinner fibrils with lateral association, while YYK forms spherical aggregates due to modified aromatic interactions and introduced hydrogen bonding.

Conclusions:

• Subtle changes in molecular structure, specifically the introduction of hydroxyl groups via tyrosine, profoundly impact tripeptide self-assembly.
• The interdependence of forces like hydrogen bonding, electrostatic repulsion, and π-π stacking leads to significant variations in nanostructure formation.
• Controlled molecular design offers a powerful strategy for tailoring peptide self-assembly into desired nanostructures.