Modulating the Nucleated Self-Assembly of Tri-β(3) -Peptides Using Cucurbit[n]urils

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Biomaterials Engineering

Background:

• Hierarchical self-assembly of peptides is crucial for developing advanced materials.
• Controlling peptide assembly is challenging but essential for creating functional supramolecular polymers.
• Host-guest interactions offer a promising strategy for precise control over self-assembly.

Purpose of the Study:

• To investigate the modulation of tri-β(3)-peptide self-assembly using cyclodextrins (CB[7] and CB[8]).
• To understand how varying cyclodextrin cavity size influences peptide aggregation.
• To explore the potential of host-guest interactions for designing functional supramolecular polymers.

Main Methods:

• Utilized β(3)-tyrosine residues within tri-peptides to facilitate host-guest interactions.
• Employed cyclodextrins CB[7] and CB[8] with different cavity sizes to interact with the peptides.
• Analyzed the distinct phases and aggregation states of self-assembling tri-β(3)-peptides under varying host-guest conditions.

Main Results:

• CB[7], with its limited cavity, acted as an inhibitor by hosting only one β(3)-tyrosine, thus restricting self-assembly.
• CB[8], with a larger cavity, formed ternary complexes with two β(3)-tyrosine residues, promoting cross-linking and larger aggregate formation.
• Distinct assembly phases of tri-β(3)-peptides were arrested by controlling the host-guest interactions with CB[7] and CB[8].

Conclusions:

• The size of the cyclodextrin cavity is a critical factor in modulating peptide self-assembly.
• Host-guest interactions with cyclodextrins provide a tunable mechanism to control supramolecular assembly.
• These findings offer general insights for designing and introducing functionality into supramolecular polymers.