Isolation and Characterization of Pepsin-Solubilized Collagen from the Skin of Black Carp (Mylopharyngdon piceus)

To make more effective use of underutilized resources, pepsin-solubilized collagen (PSC) was successfully extracted from the skin of black carp (Mylopharyngdon piceus) with a yield of 45.7% based on dry weight. The PSC comprising two identical α1-chains and one α2-chain with no disulfide bond was characterized as type I, and it contained 195 imino acid residues vs. 1000 amino acid residues. The collagen showed an absorption edge around 218 nm, which was lower than the maximum absorption wavelength of other PSC. The denaturation temperature of PSC was 25.6°C, which was lower than that of porcine collagen by approximately 11°C. The isoelectric point (pI) was estimated to be 8.23, and the collagen was soluble at an acidic pH as well as below 40 g/L NaCl. It is thought that the high yield and stability of PSC from the skin of black carp warrant its application as a new source of collagen for industrial purposes.