Comparison of the properties of collagen extracted from dried jellyfish and dried squid

With increased recent interest in the utilization of industrial by-products, finding different sources, optimizing extracting conditions and characterization of collagen extracts have recently become important research topics. This study addresses the isolation of acid-soluble and pepsin-soluble forms of collagen from dried jellyfish and squid, and their partial characterization. The properties of these proteins have been studied and a comparison made of the protein patterns of collagen extracted from marine organisms with those from other organisms, to determine which collagen subtypes are present, and in what proportions. Pepsin-soluble collagen (PSC) from dried jellyfish and dried squid contained a collagen form classified as type I, of molecular composition comparable with that of collagen type I from rat tail. Peptide maps of collagens digested by achromopeptidase were slightly different, indicating some differences in amino acid sequence or conformation. The collagen showed high solubility at acidic pH (4-5) but its solubility markedly decreased in the presence of sodium chloride (NaCl) up to 2%. Collagen type I from dried jellyfish and dried squid could be a useful alternative to mammalian collagen, with potential use in the biomedical, pharmaceutical and nutraceuticals industries.   Key words: Collagen, pepsin-soluble form, acid-soluble form, partial characterization.