Research On Preparation Of Angitensin Coverting Enzyme Inhibitory Peptides From Pinctada Martensii Protein By Enzymatic Hydrolysis

The methods of enzymatic hydrolysis, separation and purification of angiotensin coverting enzyme inhibitory peptides (ACEIP) from the edible parts of Pinctada martensii was studied in this paper, such research included 4 parts.1. The nutrients of the edible parts of Pinctada martensii was analysed. The muscle of Pinctada martensii is an good seafood which contains abundant protein. The amino acid score is 83 and it suit to prepare ACEIP.2. The crude ACE was successfully extracted from hog lung through immersed with Tris-HCl buffer solution and deposited with ammonium sulfate and separated by Sephadex G-200. The activity of crude ACE was 50.25u.3. The optimized hydrolyzed conditions was estibilished, including selection of optimal protease. The inhibitory activity of pepsin's enzymatic hydrolysate was best in 6 proteases which selected in this reseach. The optimal conditions were pH value 2.2, hydrolysis temperature 39 ℃ , enzyme concentration 3%, enzymatic hydrolysis time 6.0 hours, substrates concentration 12%. In such conditions, the enzymatic hydrolysate showed the highest ACE inhibitory activity, the IC₅₀ was 1.323mg/mL.4. Two fractions with high inhibitory activity to ACE were purificated. The IC₅₀ of fraction A and fraction B were 0.033 , 0.041 mg/ml, respectively. The dominant amino acid in fraction A and fraction B was phenylalanine(Phe), and its content in two fractions was 57.5% and 53.2%, respectively. The molecular weight of two frations was 1042 and 256, respectively.