Preparation And Physiological Activity Of Collichthys Niveatus Protein Peptide

Collichthys niveatus as a kind of low-value fishes of the sea, is one of the main targets of Chinese marine fishing. Collichthys niveatus has high content of protein, which has not been deeply processed and utilized. Prepare bioactive peptides by using its protein with enzymatic hydrolysis, which can make full use of this part of the protein, and increase the value of product.This study was mainly using Collichthys niveatus as the raw material. Select the most appropriate enzyme for single enzyme hydrolysis, and select the most two appropriate enzymes for complex enzyme hydrolysis. Use single-factor experiment and response surface experiments to optimize the enzymatic hydrolysis conditions of fish,and then carry on further isolation, purification and identification of fish protein polypeptide. Finally it studied antioxidant activity and antihypertensive activity of Collichthys niveatus protein polypeptides, and compared with the metal ion chelating and three commercially available drugs. The main conclusions are as follows:1、Hydrolyzing the Collichthys niveatus with three different types of proteases shows typsin and neutral protease have higher degree of hydrlysis and higher antioxidation, so the two proteases are choosed to hydrolyze the Collichthys niveatus with the method of compound enzymolysis. In the proccess of making the Collichthys niveatus peptides, through optimizing hydrolysis relative factors, including the enzymatic hydrolysis time, temperature,p H, and ratio of the composite. The optimum condition of Collichthys niveatus pepetides removing the DPPH is 4h hydrolysis time, 44 ℃ hydrolysis temperature and ph 6.2 with the ratio of typsin and neutral protease at 5:2. under the optimum condition. The ratio of removing DPPH is 11%±0.028, Collichthys niveatus pepetides are shown more significcant antioxidative activity.2、By mass spectrometry Collichthys niveatus polypeptide has a molecular weight of 8170.17.Through ultrafiltration, molecular weight polypeptide which was the most hypotensive effectible was molecular weight to 585.39 less than 5KDa. Molecular weight polypeptide which was the most oxidation resistant had a molecular weight of 7166.31 in 20-10 KDa.Glutamic acid content in the 20-10 KDa had reached 13.56%, followed by Leucine reaches 10.22%, once again, is alanine reached 9.49%, of these three amino acids are peptide 20-10 KDa content. Leucine content in the 5KDa, to 17.87%, followed by phenylalanine levels reached 11.62%, followed by l-lysine content was 9.98%.3、Comparison of different molecular weight comparison of the antioxidant and antihypertensive activity, antioxidant activity of different molecular weight difference, in the molecular weight of 20-10 KDa peptide solution the DPPH free radical scavenging rate is the highest, and in the molecular weight of 5KDa peptide solution is the strongest of hypotensive effect. The three metal ions chelating peptide is solved on further activity. These three kinds of metal ions were the highest antioxidant activity in the ferrous ion chelates. Hypotensive effect of magnesium ion chelates is supreme. Collichthys niveatus the hypotensive effect of protein and peptide solution came in first place in the three antihypertensive drugs on the market, and the IC50 was 1.93 mg/m L.