Synthesis of Collagen-like Peptide Polymers by Native Chemical Ligation

We report on the synthesis of high molecular weight collagen-like peptide polymers prepared by a combination of solid phase peptide synthesis, polymerization, and self-assembly. The final product is a mesh of nanofibers that maintains the characteristic circular dichroism signal for collagen triple helices and the nanofiber diameter is 10−20 nm, similar to natural collagen fibrils. This method utilizes an N-terminal cysteine and C-terminal thioester to achieve selective head to tail polymerization of peptides without the need for protecting groups and under neutral aqueous conditions in which the peptide may adopt a folded conformation. The synthesized peptide polymers were characterized by size-exclusion chromatography, circular dichroism spectroscopy, and transmission electron microscopy.