Biological function analysis of the peptides derivativesfrom milkfish(Chanos chanos) scales

• Main Authors: Chun-Hui Huang, 黃均蕙
• Other Authors: Yin-Chou Lee
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/94beff

碩士 === 國立臺灣大學 === 漁業科學研究所 === 105 === The hydrolyzed peptides of fish scale collagen are founded to have biological function such as antioxidant activity, antibacterial activity, lowering blood pressure, inhibiting tumor and so on… In this study, milkfish scales are used. The collagen content of milkfish scale are analyzed by soften the fish scale and hydrolyze the fish scale into collagen peptide. The compositions of amino acid are divided into three groups based on the molecular weight: high molecular peptides (>10kDa), medium molecular weight peptides (3-10kDa) and small molecular weight peptides (<3kDa). The molecular weight distribution of MALDI-TOF / MS is measured by small molecular weight peptides and its structure is predicted by Mobyle @ RPBS Net. The result shows that the content of collagen was 12%, and the contents of Gly, Pro and Hyp were 27%, 11% and 10.4% respectively. The molecular weight of the small molecule peptide is between 567-2775, in which the peptide 2693 contains 27 amino acids and the sequence is KPTKDGVTVAVISGEALGIKICFTSTG. There is 40% hydrophobic amino acid and the charge is +1 and the structure is β-sheet. The antioxidant capacity of milkfish peptide, >10kDa, 3-10kDa, <3kDa and peptide 2693 were 51.27%, 41.28%, 63.98%, 64.20% and 52.01%, respectively. The ferrous ion chelating ability was 40.93%, 75.99%, 68.09%, 5.76%, respectively, while peptide 2693 doesn’t have such ability. And the result of recovering is 10.26%, 17.18%, 14.11%, 8.66% and 3.06%, respectively. As for <3kDa and 2693 peptide, the minimum inhibitory concentration of Staphylococcus aureus was 7μg / ml (83.3%) and 15-30μg / ml (84.3%). The milkfish peptide produces biologically active peptides by different proteases. The differences of these biologically active peptides are depending on the different molecular weight, amino acid composition and stereospecific structure. The more hydrophobic amino acids and intramolecular hydrogen bonds are more possible to enhance antioxidant activity. The larger space of three-dimensional structure of peptide ensures more metal ions. There is more than 40% hydrophobic amino acid and positive charage in <3kDa small molecules. According to the simulation interaction between peptides 2693 and bacterial cell, we presume that the bacteria are the barrel-attack type of cell membrane. Milkfish scale peptide containing several of biological activities are verifying the effective using of aquatic waste. It is possible that fish scale peptide are using in medical, food and other industries in the future development.