Study On Physicochemical Characters And Biological Activities Of Collagen From The Body Of Sea Cucumber (Stichopus Japonicus)

From the nutritional viewpoint,sea cucumber is an ideal tonic food. Sea cucumber contains many bioactive substances and has many pharmacological functions including anticoagulant enhancing immunology, decreasing the levels of blood lipids, antibacterial activity, anticancer. About 40% of the total body wall protein is collagen, but little was known about the properties because of its extreme insolubility. In this article, collagen was prepared with limited pepsin digestion resulted in complete solubilization. On the physicochemical characters, their antioxidant and ACE inhibitory activities of collagen were carried out.(1)After pre-treatment withβ-mercaptoethanol, 0.05M NaOH, collagen was extracted from the body wall of sea cucumber by pepsin-solubilized methods. The main influencing factors were analyzed. Using yield of collagen as an index, the best conditions of preparation with pepsin were: pH2.0,4℃,m(the body wall of sea cucumber):m(HAC )=1:10,the addition of pepsin 6%,48h。(2)The physicochemical characters of collagen were studied from the body wall of sea cucumber systematically. It was a glycoprotein containing 2.7% sugar by phenol-sulfuric acid reaction. The UV-VIS of sea cucumber collagen was analyzed in accord with the characteristic of the collagen. The amino acid composition of pepsin-solubilized collagen from the body wall of sea cucumber was similar to that from typicalⅠcollagen. Based on SDS polyacrylamide gel electrophoresis (SDS-PAGE), collagen was probably a heterotrimer with a chain composition of (α1)2α2. The purities of sea cucumber collagen were higher and subunit composition and molecular weight of collagen were demonstrated, indicating that the natural structure of collagen was maintained. Denaturation temperature was 24.3℃. The...