大豆蛋白酶解肽的分子量分布及抑制ACE活性关系研究

研究不同蛋白酶作用的酶解肽表现在血管紧张素转化酶(ACE)活性抑制差异,酶解产物的水解度、分子量分布与ACE抑制率的相互关系。用胰蛋白酶、胃蛋白酶、中性蛋白酶、木瓜蛋白酶、碱性蛋白酶等五种蛋白酶对大豆分离蛋白酶解,进行了多肽增量、水解度、超滤膜分离及其ACE抑制率对比等实验。结果表明,碱性蛋白酶的多肽增量最大,胃蛋白酶次之,依次为木瓜蛋白酶和中性蛋白酶,胰蛋白酶则出现反常;水解度随着酶解的时间而增加,碱性蛋白酶的最大水解度可达到21%,依次为胃蛋白酶、木瓜蛋白酶和中性蛋白酶,最低为胰蛋白酶仅为9%左右;与此对应的碱性蛋白酶的酶解物的ACE活性抑制率为最高(44.9%),胃蛋白酶次之(43.5%)。分子量范围在1000Da以下组分对ACE的抑制效果最高,碱性蛋白酶作用获得的小分子肽组成为71.25%,胃蛋白酶的为69.35%,但其对应的ACE抑制率却为64.57%和78.49%。中性蛋白酶、木瓜蛋白酶和胰蛋白酶作用获得的小分子肽的ACE抑制率分别为45.7%、47.3%和29.6%。胃蛋白酶的降压肽制备效果为最好,其次为碱性蛋白酶、木瓜蛋白酶、中性蛋白酶和胰蛋白酶。

Study on Molecular Weight Composition of Peptides from Hydrolyzed Soybean Proteins by Protease and Their Activities of Inhibiting ACE

In this research, difference soybean peptides were prepared by hydrolyzing soybean protein isolate with alcalase, pepsin, trypsinase,p apaina ndn eutrase respectively,a ndt hed ifference oft heira ngiotensinc onverting enzyme (ACE)i nhibiting activities was studied. Comparison experiments on peptides increments, relationship between degree of hydrolysis (DH) and ACE inhibitoryr ate, relation betweenu ltrafiltrateo fp eptidesa ndA CEi nhibitoryr atea nde lectrophoretics eparation werec onducted. The result showed that the peptides increments by alcalase hydrolysis were the largest, and the sequent order in turn was pepsin >papain>neutrase, but trypsinase was abnormal. The degree of hydrolysis (DH) increased with prolongation of time. The biggest Dh of alcalase was 21%, and the sequent order in turn was pepsin>papain>neutrase, but trypsinase was only 9%. ACE inhibitory rate of alcalase, pepsin, papain, neutrase and trypsinase hydrolysates at the biggest DH, were 44.9%, 43.5%, 23.1%, 23.5% and 15.7% respectively. Peptides with above 1000 daltons molecular weight have the strongest inhibitory effects on ACE. Small molecular peptides by alcalase and pepsin amounted for 71.3% and 69.4% of all the peptides respectively, and the ACE inhibitory rate of the small molecular peptides by alcalase, pepsin, papain, neutrase and trypsinase were 64.57%, 78.49%, 47.3%, 45.7% and 29.6% respectively. So it can be concluded that papain was optimum for ACE inhibiting peptide preparation among 5kinds of protease, and the sequent order in ture: alcalase>papain>neutrase>trypsinase.