螺旋藻蛋白水解产物对ACE抑制活性的研究

采用胃蛋白酶和胰蛋白酶水解螺旋藻藻胆蛋白制备ACE 抑制肽，通过体外实验测定其ACE 抑制率，以ACE 抑制率为指标确定两种蛋白酶的水解条件。结果表明：胃蛋白酶水解条件为：水解温度37℃，酶与底物比1:50，pH3.0，底物质量分数5%，水解产物的ACE 抑制率为82.16%，其IC50 值为0.104mg/ml；胰蛋白酶水解条件为：水解温度42℃，酶与底物1:50，pH8.0，底物质量分数6%，水解产物的ACE 抑制率为93.54%，其IC50值为0.017mg/ml。此外，胃蛋白酶水解产物再用胰蛋白酶水解，其产物的IC50 值为0.087mg/ml。

ACE Inhibitory Activity of Hydrolysates of Phycobiliproteins from Spirulina

ACE inhibitory peptides were prepared from Spirulina phycobiliproteins by pepsin or trypsin-catalyzed hydrolysis and the ACE inhibitory activities were determined by in vitro spectrophotometric assay so as to optimize the hydrolysis conditions by orthogonal factorial design. The results showed the conditions for pepsin-catalyzed hydrolysis were as follows: enzyme/ substrate ratio 1:50, pH 3.0 and substrate concentration 5% (m/V), and hydrolysis temperature 37 ℃ for a hydrolysis duration of 120 min, and these conditions resulted in 82.16% of the ACE inhibition rate and the IC50 reached 0.104 mg/ml; the optimal conditions for trypsin-catalyzed hydrolysis were as follows: enzyme/substrate ratio 1:50, pH 8.0 and substrate concentration 6% (m/V), and hydrolysis temperature 42 ℃ for a hydrolysis duration of 160 min; and the IC50 of trypsin-catalyzed hydrolysates of Spirulina phycobiliproteins by pepsin (both under the optimized conditions) reached 0.087 mg/ml.