Abstract:The collagen from sea cucumber Apostichopus japonicus body wall was extracted by pepsin digestion under acidic condition. After separation and purification, the collagen was heated at varied temperatures, and then the biochemical characteristics were determined by the methods of SDS-PAGE and FT-IR scanning. The result indicated that the extracted collagen was of high purity and with integrated triple-helix structure; After being heated at 40 ℃, the secondary structure of the collagen was destroyed, while some primary structure was partially destroyed，with disappearence of α chain and β chain, and the molecular weight of peptide chains reduced(<100kDa); At 70 ℃, the peptide chains began to aggregate and shrink, and the molecular weight increased; Up to 80 ℃, the peptide chains further contracted with 120kDa MW but still maintained some secondary structure; When heated at above 100 ℃, the primary structure of the collagen was destroyed seriously.
