Biochemical properties of bone and scale collagens isolated from the subtropical fish black drum (Pogonia cromis) and sheepshead seabream (Archosargus probatocephalus)

Acid-soluble collagen (ASC) and pepsin-solubilized collagen (PSC) were isolated from the bones and scales of black drum (Pogonia cromis) and sheepshead seabream (Archosargus probatocephalus) caught in the Gulf of Mexico. ASC and PSC were analyzed for molecular weight by SDS–PAGE, amino acid composition, secondary structure, and denaturation temperature. The molecular masses of the collagen subunits were about 130 kDa for α1 and 110 kDa for α2, respectively. The amino acid composition of the PSCs was closer to that of calf skin ASC than to that of cod skin ASC. The melting temperatures of ASC and PSC were >34 °C. Intrinsic viscosity of the PSCs was similar to the intrinsic viscosity of collagen from fish species such as hake, cod, and catfish. Black drum and sheepshead bone and scale collagens were typical type-I collagens and may find applications in the functional food, cosmetic, biomedical, and pharmaceutical industries.