Designing stable, hierarchical peptide fibers from block co-polypeptide sequences

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Natural materials like collagen exhibit complex hierarchical organization.
• Synthetic materials currently lack the controlled assembly and stability seen in natural counterparts.
• Peptide assembly is governed by intricate hydrophobic, electrostatic, and secondary structure interactions, making precise control difficult.

Purpose of the Study:

• To develop a synthetic strategy for creating peptide-based materials with controlled morphology, stability, and hierarchical organization.
• To design block co-polypeptides with tunable properties for predictable self-assembly.
• To achieve hierarchical assembly of synthetic peptide structures.

Main Methods:

• Synthesis of block co-polypeptides with varied hydrophobicity and secondary structure formation propensity.
• Characterization of self-assembly behavior under different conditions.
• Investigation of nanotube stability across a range of pH and temperatures.
• Directed hierarchical assembly into bundled fibers via pH control and zwitterionic interactions.

Main Results:

• Identified a specific block co-polypeptide sequence yielding thermodynamically favored, high-aspect ratio nanotubes.
• Demonstrated exceptional nanotube stability over a broad pH range (2-12) and elevated temperatures (up to 80 °C).
• Achieved hierarchical assembly of nanotubes into bundled fibers by manipulating pH and exploiting zwitterionic charge behavior.

Conclusions:

• A rational block co-polypeptide design strategy enables precise control over peptide assembly.
• The developed nanotubes offer superior stability and tunable hierarchical assembly capabilities.
• This approach provides a versatile platform for creating advanced peptide-based hierarchical materials.