Sequence Adaptive Peptide-Polysaccharide Nanostructures by Biocatalytic Self-Assembly.

Area of Science:

• Biomaterials Science
• Supramolecular Chemistry
• Nanotechnology

Background:

• Peptide-polysaccharide coassemblies form nanostructures with tunable morphologies.
• Dynamic control over these nanostructures is crucial for advanced biomaterials.

Purpose of the Study:

• To demonstrate in situ enzymatic exchange of dipeptide sequences in peptide amphiphile/polysaccharide coassemblies.
• To achieve dynamic formation and degradation of different nanostructures based on polysaccharide presence.

Main Methods:

• A one-pot system using Fmoc-cysteic acid (CA), Fmoc-lysine (K), and phenylalanine amide (F) with thermolysin.
• Enzymatic hydrolysis and amide formation to create a dynamic peptide library (CAF and KF).
• Addition of cationic chitosan or anionic heparin to induce selective peptide amplification and nanostructure formation.

Main Results:

• Chitosan addition selectively amplified CAF, forming nanosheets via coassembly.
• Heparin addition led to KF formation and nanotube morphology.
• Sequential addition of polysaccharides demonstrated dynamic morphology changes.

Conclusions:

• This study demonstrates the first instance of accessing different peptide sequences and nanostructures based on biopolymer presence.
• The findings suggest potential for designing adaptive biomaterials with dynamic morphogenesis capabilities.