Abstract
Collagen, the most abundant protein in mammals, has been widely used in biomedical materials. Searching for an effective way to assemble short mimetic collagen peptides into a higher order structure has been an emerging topic for the preparation of collagen-related biomaterials. In this work, we have incorporated histidine residue into two mimetic collagen peptides to promote the self-assembly of short collagen triple helices into supermolecular structure via His-metal coordination. Our results indicate that His-metal coordination can serve as an effective force to assemble mimetic collagen peptides into large scale structures and their topology depends on metal ions and His-metal coordination sites. Furthermore, the process of self-assembly can be reversed upon adding the cation chelator, EDTA, in solution. In addition, we have introduced a cationic residue into the N-terminus and an aromatic residue into the C-terminus of a collagen-related peptide which can generate favorable cation-π interactions between the termini of collagen triple helices. The experimental results demonstrate that cation-π interactions can promote the self-assembly of collagen triple helices into higher-order fibril structures in a head-to-tail manner. The work shows that cation-π interactions can serve as an effective force in preparing collagen-related biomaterials.