Isolation and characterization of collagen from the skin of deep-sea redfish (Sebastes mentella)

To make more effective use of underutilized resources, acid-solubilized collagen (ASC) and pepsin-solubilized collagen (PSC) were isolated from the skin of deep-sea redfish (Sebastes mentella) and characterized for their potential in commercial applications. The yield of ASC (47.5%) was lower compared to PSC (92.2%), but the purity of ASC was significantly higher. The instrinsic viscosity of ASC (15.9 dL/g) was greater than PSC (14.6 dL/g), indicating a higher average molecular weight of ASC on amount of the high proportion of polymers of collagen. The denaturation temperature of ASC and PSC were 16.1 and 15.7 degrees C, respectively, suggesting the triple helical structure of PSC was still predominant. The amino acid profiles of ASC and PSC were similar with lower imino acid content than most other species, which might be the reason for the lower denaturation temperature. SDS-PAGE and FTIR showed that both ASC and PSC were type I mainly with slight stucture differences. ASC held its triple helical structure well, and possessed a higher extent of intermolecular cross-link. While the structure of PSC was change slightly due to the loss of N- and C-terminus domains, the triple helical structure was still predominat as a result of the formation of more and/or stronger hydrogen bond.