Metal Ion-Induced Cross-Linking in Mucin-Inspired Peptide Hydrogels

Area of Science:

• Biomaterials Science
• Supramolecular Chemistry
• Glycobiology

Background:

• Mucus, a biological hydrogel, protects mammalian mucosal surfaces but its complex mucin composition hinders precise structure-property studies.
• Chemically defined peptide models offer a controllable alternative for investigating glycoprotein properties and developing new materials.

Purpose of the Study:

• To design and characterize a library of synthetic glycopeptide hydrogels.
• To investigate the influence of glycan identity, histidine position, and divalent metal ions on hydrogel properties.
• To explore the potential of these glycopeptide hydrogels for fundamental research and biomedical applications.

Main Methods:

• Synthesis of histidine- and monosaccharide-containing coiled coil peptides.
• Hydrogel formation induction using divalent metal ions (Cu2+, Zn2+, Ca2+, Fe2+).
• Characterization using rheology, circular dichroism, and transmission electron microscopy.

Main Results:

• The synthesized glycopeptide peptides successfully formed hydrogels with varying degrees of crosslinking in the presence of divalent metal ions.
• Rheological and structural analyses revealed distinct viscoelastic properties and global structures for the different glycopeptide materials.
• The study identified a significant interplay between glycan identity, histidine position, and the type of divalent metal ion in determining the hydrogel's mechanical strength.

Conclusions:

• Chemically defined glycopeptide hydrogels can be synthesized as functional mimics of natural mucus.
• The mechanical properties of these synthetic hydrogels are precisely tunable by altering glycan structure, peptide sequence, and metal ion coordination.
• These findings provide a foundation for developing advanced glycopeptide-based biomaterials with tailored properties for diverse applications.