Influence of telopeptides on the structural and physical properties of polymeric and monomeric acid-soluble type I collagen

Abstract

Currently two factors hinder the use of collagen as building block of regenerative devices: the limited mechanical strength in aqueous environment, and potential antigenicity. Polymeric collagen is naturally found in the cross-linked state and is mechanically tougher than the monomeric, acid-soluble collagen ex vivo. The antigenicity of collagen, on the other hand, is mainly ascribed to inter-species variations in amino acid sequences of the non-helical terminal telopeptides. These telopeptides can be removed through enzymatic treatment to produce atelocollagen, although the effect of this cleavage on triple helix organization, amino acidic composition and thermal properties is often disregarded. Here, we compare the structural, chemical and physical properties of polymeric and monomeric type I collagen with and without telopeptides, in an effort to elucidate the influence of either mature covalent crosslinks or telopeptides. Circular dichroism (CD) was used to examine the triple helical conformation and quantify the denaturation temperature (T) of both monomeric collagen (36.5°C) and monomeric atelocollagen (35.5°C). CD measurements were combined with differential scanning calorimetry (DSC) in order to gain insight into the triple helix-to-coil thermal transition and shrinkage temperature (T) of polymeric atelo collagen (44.8°C), polymeric collagen (62.7°C), monomeric atelo collagen (51.4°C) and monomeric collagen (66.5°C). Structural and thermal analysis was combined with high pressure liquid chromatography (HPLC) to determine the content of specific collagen amino acidic residues used as markers for the presence of telopeptides and mature crosslinks. Hydroxylamine was used as the marker for polymeric collagen, and had a total content of 9.66% for both polymeric and polymeric atelo collagen; tyrosine was used as the marker for telopeptide cleavage, was expressed as 0.526% of the content of polymeric collagen and the partially-reduced content of 0.39% for atelocollagen.

Rapid Photoinduced Single Cell Detachment from Gold Nanoparticle-Embedded Collagen Gels with Low Denaturation Temperature

“…Both sol-gel and hydrogel transition temperatures then affected the collagen fibril networks as macroscopic changes. The thermal properties of collagen materials were already reported by other groups [11][12][13][17][18][19]. Although the denaturation temperature was dependent in the sample conditions such as the water content, our results are not inconsistent with previous reports.…”

“…Acid-extracted collagens maintain the telopeptide regions, but enzyme-treated collagens do not. It is reported that the telopeptide affects the crosslinking as well as the immunogenicity of the collagen [13,14]. Therefore, the physicochemical properties of collagen materials largely depend on the collagen origin and the collagen preparation procedures [11][12][13].…”

The application of collagen in advanced wound dressings

“…telopeptides, with up to half of the amino acid residues in these regions exhibiting interspecies variation. Telopeptide-free collagen, also called atelocollagen, can be obtained via pepsin-induced extraction [31], whose yield is reported to be higher compared to acidic extraction [32]. The introduction of pepsin in the extraction medium allows for the selective cleavage of peptide bonds located in the terminal non-helical regions, potentially reducing collagen antigenicity.…”

Collagen Hydrolysates for Skin Protection: Oral Administration and Topical Formulation

“…However, the degradation of collagen produces hydrolyzed collagen (HC), which consists of segmented proteins with low molecular weight (Mw) between 1 kDa and 10 kDa [16]. HC is obtained by denaturation of native collagen followed by an enzymatic process that breaks down the protein chains into small peptides cleaving the protein at specific amide bonds [17][18][19]. The use of natural peptides like collagen hydrolysates has been widely utilized due to their excellent biocompatibility, easy biodegradability, and weak antigenicity [20].…”