酶解蚕蛹蛋白制备血管紧张素转换酶抑制肽的工艺优化

Optimization of Technology for Preparation of Angiotensin-converting Enzyme Inhibitory Peptides from Silkworm Pupal Protein by Enzymatic Hydrolysis

采用碱性蛋白酶水解蚕蛹蛋白,制备血管紧张素转换酶(angiotensin-converting enzyme,ACE)抑制肽,是蚕蛹蛋白深度开发的途径之一。以ACE抑制率为响应值,用响应面分析法研究酶解温度、酶解pH和加酶量等因素对酶解产物的ACE抑制活性的影响,优化制备工艺。结果表明,各因素对制备ACE抑制肽的活性影响程度由大到小依次为酶解pH、酶解温度、加酶量。获得碱性蛋白酶水解蚕蛹蛋白制备ACE抑制肽的最佳工艺条件为:酶解温度50.8℃,酶解pH 9.0,加酶量3 500 U/g。在此条件下,蚕蛹蛋白酶解产物对ACE的理论抑制率最高可达96.67%,验证值为96.49%±1.75%,IC50值为0.102 mg/mL,预测模型可靠性高,可应用于蚕蛹ACE抑制肽的酶法制备。

Hydrolysis of silkworm pupal proteins with alcalase for preparation of angiotensin-converting enzyme（ACE） inhibitory peptides is one of the important ways to have in depth utilization of silkworm pupal proteins.Taking ACE-inhibitory rate as the response value,effects of hydrolysis temperature,hydrolysis pH,and enzyme dosage on ACE-inhibitory activity of the hydrolysates were analyzed with response surface methodology for optimization of the preparation technology.The results showed that importance of the three factors affecting activity of ACE-inhibitory peptides from high to low was in the order of hydrolysis pH,hydrolysis temperature,and enzyme dosage.The optimized process parameters for preparation of angiotensin-converting enzyme（ACE） inhibitory peptides from alcalase hydrolyzed silkworm pupal proteins were as follows： hydrolysis temperature 50.8 ℃,hydrolysis pH 9.0,and enzyme dosage 3 500 U/g.Under this condition,the highest ACE-inhibitory rate of the hydrolysate from silkworm pupal proteins was 96.67% in theory and the actual value was 96.49%±1.75%,IC50 value was 0.102 mg/mL.The result indicates that the established prediction model is reliable and is applicable to enzymatic preparation of ACE-inhibitory peptides from silkworm pupal proteins.