Hierarchical Assembly of Collagen Peptide Triple Helices into Curved Disks and Metal Ion-Promoted Hollow Spheres

Abstract

A 27 amino acid collagen-based peptide (Hbyp3) was designed to radially display nine hydrophobic bipyridine moieties from a triple helical scaffold. Self-assembly of such functionalized triple helices led to the formation of micrometer-scaled disks with a curved morphology, presumably mediated by aromatic interactions, with a height that is in the range of the length of the triple helical peptide. Higher order assembly of these curved disks into micrometer-sized hollow spheres was accomplished through metal-ligand interactions between bipyridine groups of the disks and metal ions such as Fe(II), Co(II), Zn(II) and Cu(II). The thickness of the shell of these hollow spheres corresponds well with the thickness of the collagen peptide-based triple helix and the corresponding self-assembled disks. Addition of a metal ion chelator was found to reverse the assembly of the hollow spheres back to the curved disk structures. These data support the formation of the hollow spheres from the self-assembled disks of Hbyp3 upon addition of metal ions.

Self-Assembly of Left- and Right-Handed Molecular Screws

“…The crystalline sheets formed during self-assembly suggest a uniform supramolecular structure. Wide-angle X-ray scattering (WAXS) was used to characterize peptide organization 15,23,24 . WAXS profiles confirmed the existence of triple helices, and allowed us to compare inter-helical distances between homo- and heterochiral associations.…”

Molecular, Local, and Network-Level Basis for the Enhanced Stiffness of Hydrogel Networks Formed from Coassembled Racemic Peptides: Predictions from Pauling and Corey

“…Self-assembling peptides can form a broad array of supramolecular structures including sheets, 1−5 disks, 6 spheres, 7 barrels, 8 tubes, 9−12 and fibrils. 13−22 Fibrils are privileged structures capable of higher order assembly leading to the formation of networks that constitute the formation of macroscopic hydrogels.…”

Ln3+‐Mediated Self‐Assembly of a Collagen Peptide into Luminescent Banded Helical Nanoropes

“…For instance, fibers have been generated by utilizing synthesized peptides with a modified cysteine knot, electrostatic interactions, π–π stacking, π–cation interactions, metal–ligand interactions, metal‐mediated tandem co‐assembly, peptide amphiphiles, triple helical nucleation, and hydrophobic interactions . Other well programmed higher‐order structures, such as microflorettes, meshes, microtubes, hollow spheres, nanodisks, and nanosheets have also been achieved using various collagen peptide‐based approaches. Some of these peptide materials have attained specific functions for nanowires, three‐dimensional cell culture, and platelet activation …”