Nanoscale click-reactive scaffolds from peptide self-assembly.

Area of Science:

• Organic nanotechnology
• Materials science
• Biotechnology

Background:

• Proteins and peptides self-assemble into stable amyloid fibrils, useful for organic nanotechnology.
• Current methods limit cargo conjugation to amyloid fibrils due to steric hindrance or harsh assembly conditions.
• A general post-assembly conjugation method is needed for amyloid fibrils.

Purpose of the Study:

• To design amyloid fibrils capable of post-assembly functionalization using bioorthogonal click chemistry.
• To demonstrate the conjugation of azide-functionalized molecules to pre-formed, alkyne-displaying amyloid fibrils.

Main Methods:

• Designed an amyloidogenic peptide (TTR105-115 fragment) displaying surface alkyne functionality.
• Formed amyloid fibrils and performed Huisgen cycloaddition (click reaction) with azide-containing molecules.
• Utilized mass spectrometry and total internal reflection fluorescence microscopy for analysis.

Main Results:

• Successfully formed amyloid fibrils displaying surface alkyne groups.
• Demonstrated efficient click reaction between fibrils and azide-functionalized amino acids and dyes.
• Confirmed that fibril structure was maintained during post-assembly functionalization.

Conclusions:

• This is the first report of amyloid fibrils undergoing click reactions after their formation.
• The post-assembly approach protects sensitive molecules from harsh fibril formation conditions.
• Enables broader applications in bionanotechnology and materials science with diverse protein ligands.