Terminal repeats impact collagen triple-helix stability through hydrogen bonding.

Nearly 30% of human proteins have tandem repeating sequences. Structural understanding of the terminal repeats is well-established for many repeat proteins with the common α-helix and β-sheet foldings. By contrast, the sequence-structure interplay of the terminal repeats of the collagen triple-helix remains to be fully explored.

Peptoid Residues Make Diverse, Hyperstable Collagen Triple-Helices.

As the only ribosomally encoded N-substituted amino acid, proline promotes distinct secondary protein structures. The high proline content in collagen, the most abundant protein in the human body, is crucial to forming its hallmark structure: the triple-helix. For over five decades, proline has been considered compulsory for synthetic designs aimed at recapitulating collagen's structure and properties.

Collagen denaturation is initiated upon tissue yield in both positional and energy-storing tendons.

Tendons are collagenous soft tissues that transmit loads between muscles and bones. Depending on their anatomical function, tendons are classified as positional or energy-storing with differing biomechanical and biochemical properties. We recently demonstrated that during monotonic stretch of positional tendons, permanent denatured collagen begins accumulating upon departing the linear region of the stress-strain curve.

Enrichment of Collagen Fragments Using Dimeric Collagen Hybridizing Peptide for Urinary Collagenomics.

Collagen remodeling in normal and pathologic conditions releases numerous collagen fragments into biological fluids. Although a few collagen fragments have been tested as biomarkers for disease indication, most occur at trace levels, making them nearly impossible to detect even with modern analytical tools. Here we report a new way to enrich collagen fragments that allows complete peptidomic analysis of collagen fragments in urine.

Non-covalent photo-patterning of gelatin matrices using caged collagen mimetic peptides.

To address the downside of conventional photo-patterning which can alter the chemical composition of protein scaffolds, we developed a non-covalent photo-patterning strategy for gelatin (denatured collagen) hydrogels that utilizes UV activated triple helical hybridization of caged collagen mimetic peptide (caged CMP). Here we present 2D and 3D photo-patterning of gelatin hydrogels enabled by the caged CMP derivatives, as well as creation of concentration gradients of CMPs. CMP's specificity for binding to gelatin allows patterning of almost any synthetic or natural gelatin-containing matrix, such as gelatin-methacrylate hydrogels and corneal tissues.