Isolation and partial characterization of pepsin-soluble collagen from the skin of grass carp (Ctenopharyngodon idella)

Pepsin-soluble collagen was extracted from the skin of grass carp (Ctenopharyngodon idella) with a yield of 46.6%, on a dry weight basis. Electrophoretic patterns showed that the collagen contained α1 and α2 chains, similar to those of calf skin collagen. The imino acid content of the collagen from grass carp skin was much lower than those of mammalian’s collagens, as also were the transition temperature and denaturation temperature which were only 24.6 °C and 28.4 °C respectively. Peptide maps of the collagen digested by trypsin and V8 protease showed different peptide fragments from those of calf skin collagen and other fish skin collagens, suggesting differences in amino acid sequences and collagen conformation. In addition, the lyophilized collagen sponge from grass carp skin had a uniform and regular network structure, just like calf skin collagen sponge. These results suggest that grass carp skin has potential for use as a supplementary source of collagen.