研究了以条斑紫菜为原料,采用木瓜蛋白酶制备紫菜蛋白活性寡肽,以ACE抑制率为评价指标,研究不同水解条件下酶解液的降血压活性,优化酶解工艺条件并测定酶解物的分子量。优化后的木瓜蛋白酶酶解工艺条件为pH7.5,温度50℃,底物浓度30 mg/mL,酶添加量600 U/g,在此条件下,水解4 h的酶解产物抑制活性达30%以上,ACE抑制肽的半抑制浓度IC50值为4.48 mg/mL。将制备的酶解液进行层析分析,测得具有降血压活性的紫菜蛋白酶解产物是相对分子质量小于2 000的活性肽。

In the paper,the preparation of bioactive oligopeptides from Porphyra yezoensis proteins in the presence of papain was studied.The ACE inhibitory activity was used as response to optimize the enzymatic conditions.The molecular weight distribution of the hydrolysates was determined by gel filtration chromatography on SephadexG-15 column.The result of which showed that the optimum conditions were pH 7.5,temperature 50℃,substrate concentration 30mg/mL,addition amount of enzyme 600 U/g.Under such conditions,and hydrolyzing for 4 hours,the inhibitory activity of the hydrolysates reached up to 30%,with IC50 value reaching 4.48mg/mL.The hydrolysates of Porphyra yezoensis were then determined by chromatography,the result of which showed that the hydrolysates of antihypertensive activity from Porphyra yezoensis proteins was mainly oligopeptide with molecular weight less than 2000.