两步法制备高活性酪蛋白ACE抑制肽的工艺参数研究

Two-step Alkalinase Hydrolysis for Production of Casein-derived ACE Inhibitory Peptides with High Activity

为了制备高活性ACE抑制肽,研究两步法高活性酪蛋白ACE抑制肽的制备工艺条件参数。利用枯草杆菌碱性蛋白酶55℃水解酪蛋白6h制备酪蛋白ACE抑制肽,IC50为38.6μg/mL;采用相同的酶进行Plastein反应来修饰酪蛋白ACE抑制肽,并应用响应面分析法优化修饰反应条件。固定酪蛋白ACE抑制肽质量分数为35%,以ACE抑制肽的游离氨基减少量为指标,优化的修饰反应条件为酶添加量7.7kU/g蛋白质、温度42.7℃、反应时间6h,在此条件下,酪蛋白ACE抑制肽的游离氨基减少量达到179.72μmol/g蛋白质。ACE抑制活性分析结果表明,修饰后ACE抑制肽的抑制活性显著提高且与修饰反应程度相关,IC50可降至0.5μg/mL。

The ACE inhibitory peptides derived from casein hydrolyzed with alkaline protease from Bacillus subtilis at 55 ℃ for 6 h exhibited an IC50 of 38.6μg/mL. To enhance their activity, they were modified via the plastein reaction catalyzed by the enzyme. Moreover, response surface methodology was employed to investigate the optimal values of plastein reaction parameters including enzyme dosage and reaction temperature and time. Results showed that after the optimal reaction for 6 h at 42.7 ℃ and an enzyme dosage of 7.7 kU/g protein, the content of free amino groups in the peptides were decreased by up to 179.72 μmol/g protein. The optimized plastein reaction resulted in an obvious enhancement of casein-derived ACE inhibitory peptides, which was related to the reaction degree and the IC50 of the modified ACE inhibitory peptides was reduced to 0.5μg/mL.