Influence of telopeptides, fibrils and crosslinking on physicochemical properties of Type I collagen films

Abstract

Type I collagen is widely used in various different forms for research and commercial applications. Different forms of collagen may be classified according to their source, extraction method, crosslinking and resultant ultrastructure. In this study, afibrillar and reconstituted fibrillar films, derived from acid soluble and pepsin digested Type I collagen, were analysed using Lateral Force Microscopy (LFM), Fourier Transform Infra-Red Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and enzymatic stability assays to asses the influence of telopeptides, fibrils and crosslinking. LFM proved to be a useful technique to confirm an afibrillar/fibrillar ultrastructure and to elucidate fibril diameters. FTIR has proved insensitive to ultrastructural differences involving telopeptides and fibrils. DSC results showed a significant increase in T(d) for crosslinked samples (+22-28 degrees C), and demonstrated that the thermal behaviour of hydrated, afibrillar films is more akin to reconstituted fibrillar films than monomeric solutions. The enzymatic stability assay has provided new evidence to show that afibrillar films of Type I collagen can be significantly more resistant to collagenase (by up to 3.5 times), than reconstituted fibrillar films, as a direct consequence of the different spatial arrangement of collagen molecules. A novel mechanism for this phenomenon is proposed and discussed. Additionally, the presence of telopeptide regions in afibrillar tropocollagen samples has been shown to increase resistance to collagenase by greater than 3.5 times compared to counterpart afibrillar atelocollagen samples. One-factor ANOVA analysis, with Fisher's LSD post-hoc test, confirms these key findings to be of statistical significance (P < 0.05). The profound physicochemical effects of collagen ultrastructure demonstrated in this study reiterates the need for comprehensive materials disclosure and classification when using these biomaterials.

Characterization of a Novel Subtilisin-like Protease Myroicolsin from Deep Sea Bacterium Myroides profundi D25 and Molecular Insight into Its Collagenolytic Mechanism

“…Collagen telopeptides are nontriple-helical domains at the N and C termini of collagen monomers. Cross-links between neighboring telopeptides are essential for stabilizing the structure of mature collagen microfibrils (9,52). Because of the hydrolysis of proteoglycans and telopeptides by myroicolsin, the complex hierarchical structure of collagen fiber was destroyed, and free collagen monomers were produced.…”

Matrix Metalloproteinases and Other Matrix Proteinases in Relation to Cariology: The Era of ‘Dentin Degradomics'

“…Cleavage of the C-and N-terminal telopeptide (containing the carboxy-and aminoterminal cross-links, respectively [Orgel et al, 2000]) results in the loss of terminal ends of the collagen molecule. The enzymes capable of cleaving telopeptides are collectively called telopeptidases, and in relation to dentin pathologies include at least MMP-2 and MMP-9 [Okada et al, 1995;Garnero et al, 1998Garnero et al, , 2003Osorio et al, 2011], cathepsin K [Garnero et al, 1998[Garnero et al, , 2003], pepsin [Walton et al, 2010] and trypsin [Mirigian et al, 2013]. Type I collagen telopeptide contains recognition sites for the gelatinase fibronectin-like domain [Steffensen et al, 1995], indicating that MMP-2 and MMP-9 telopeptidase activity may be totally separate from the gelatinolytic activity of these enzymes.…”

“…Type I collagen telopeptide contains recognition sites for the gelatinase fibronectin-like domain [Steffensen et al, 1995], indicating that MMP-2 and MMP-9 telopeptidase activity may be totally separate from the gelatinolytic activity of these enzymes. It is interesting to note that neither pepsin nor trypsin have any marked cleavage activity against type I collagen helical parts [Walton et al, 2010;Mirigian et al, 2013]. Therefore, the role of gastric enzymes in the matrix degradation in erosion [Schlueter et al, 2010[Schlueter et al, , 2012b] may relate to telopeptidase activity and activation of other collagenolytic enzymes [Mirigian et al, 2013], e.g.…”

Macrophage-mediated degradation of crosslinked collagen scaffolds

“…Previous studies have investigated collagenase-driven degradation of collagen scaffolds [30,31]. The present study assesses the cell-mediated biodegradation of different collagen scaffolds in vitro and correlates the chemical degradation of scaffolds with an in vitro model of scaffold degradation.…”