PREPARATION AND CHARACTERIZATION OF PEPSIN-SOLUBILIZED TYPE I COLLAGEN FROM THE SCALES OF SNAKEHEAD (OPHIOCEPHALUS ARGUS)

Abstract

ABSTRACT Pepsin-solubilized collagen prepared from the scales of snakehead (Ophiocephalus argus) was separated into two fractions, major and minor, by NaCl precipitation. The results of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), amino acid composition, and secondary structure showed that the major collagen was typical type I collagen; in contrast, the minor collagen might be classified as type V collagen from the SDS-PAGE patterns and precipitation properties by NaCl. A sharp decrease in solubility of type I collagen was observed at the NaCl concentration of 40 g/L. The maximum and the minimum solubilities of collagen were observed at pH 3 and 8, respectively. Peptide maps of type I collagen digested by trypsin and V8 protease were different from those of calfskin and fish skin collagens. The imino acid content of type I collagen was lower than those of mammalian collagens and so did its denaturation temperature that was 30.3C obtained by viscosity measurement. PRACTICAL APPLICATIONS Collagen has been widely utilized as a material for foods, cosmetics, and pharmaceuticals. However, the use of collagen-derived products from land animals (e.g., bovine and pig) has been called into question because of foot-and-mouth disease crisis etc. Aquatic animal offals, which are readily available and inexpensive, seem to be safe sources for extraction of collagen. This work reports on preparation and characterization of collagen from snakehead scales, which will have potential in supplementing the skins and bones of land animals as an important collagen resource for use in functional food, biomedical, and cosmetic industries.