Supramolecular Assembly of Electrostatically Stabilized, Hydroxyproline-Lacking Collagen-Mimetic Peptides

Abstract

The mechanical and biological functions of the native collagens remain an inspiration in materials design, but widespread application of de novo collagens has been limited in part by the need for hydroxylated proline in the formation of stable triple helical structures. In order to address this continued need and to expand the potential for recombinant expression of functional, hydroxyproline-lacking collagen-mimetic peptides, we have designed a hydrophilic, non-repetitive, and thermally stable collagen-mimetic peptide via the incorporation of triple-helix-stabilizing charged triplets. The peptide sequence is also equipped with a type III-collagen-mimetic cystine knot at the C-terminus to facilitate covalent crosslinking of the triple helix via simple air oxidation. Circular dichroic (CD) studies of this collagen-mimetic peptide revealed a typical, thermally stable, collagen triple helix signature, with a weak positive maximum at 225 nm, and a triple helix melting temperature (Tm) of 35 °C and 43 °C for the reduced and oxidized forms respectively. The thermal behavior was confirmed via analysis by differential scanning calorimetry. Interestingly, this hydroxyproline-lacking, collagen-mimetic peptide also assembles into nanorods and microfibrillar structures as observed via transmission electron microscopy. The identification and demonstrated useful collagen-mimetic properties of this peptide suggests important opportunities in the recombinant design of new collagen-based biomaterials.

ECM turnover-stimulated gene delivery through collagen-mimetic peptide-plasmid integration in collagen

“…In this work, we evaluated the persistence of the collagen-polyplex interaction and the capacity to drive gene delivery via endocytic collagen turnover. CMP-modified PEI polyplexes were incorporated into collagen gels [50–52] and long-term transfection studies and DNA integrity assays were employed to monitor polyplex efficacy and stability. Collagen-polyplex co-internalization studies and gene silencing experiments were used to assess mechanisms of cellular uptake, particularly via caveolar mechanisms [53, 54].…”

Noncovalent Modulation of the Inverse Temperature Transition and Self-Assembly of Elastin-b-Collagen-like Peptide Bioconjugates

“…CLPs have been shown to mimic the triple helix conformation of native collagen, 8 and thus have served as model systems for triple helix structure and the stabilization effect of specific amino acid residues in collagens, 9 as well as to mimic collagen fibril formation. 10 Additionally, recent studies have illustrated that single-stranded CLPs have a strong propensity to bind native collagen via a strand invasion process. 11 The high propensity of CLPs for collagen permits detection of minute quantities of collagen (e.g., 5 ng) 12 with substantial promise for staining collagens in human tissues (e.g., skin, cornea, bone, 12 and liver 13 ), especially those with high ECM turnover (e.g., prostate tumor xenografts, joints, and articular cartilage 14 ).…”

Collagen mimetic peptides: progress towards functional applications

“…This research activity comes somewhat late compared to other synthetic protein-based biomaterials, such as α-helix and β-sheet proteins and peptides whose supramolecular assembly is already being widely used for practical applications and clinical trials. 93,94 Considering collagen’s critical role in tissue regeneration and its association with numerous pathologic conditions, we believe that continued research with CMPs 95 will eventually lead to the design of artificial tissue scaffolds and collagen targeting system that will find practical biomedical use. Fibrous collagens are abundant in nature and are readily available in various forms (e.g.…”