米糠蛋白酶解产物中血管紧张素转化酶抑制剂的研究

目的从米糠蛋白酶解产物中提取制备血管紧张素转化酶（ACE）抑制剂。方法采用等电点沉淀的方法提取米糠中的蛋白质，先后经胃蛋白酶和胰蛋白酶水解后，采用凝胶层析法分离酶解组分，检测各组分ACE抑制性，对活性较强的组分用阳离子交换树脂SP—Sephadex C-25作进一步的分离检测。结果获得的ACE抑制肽分子量为307．1，其等电点在5～6之间。它在消化液中具有稳定性。其IC50为0．061mg／ml。结论从米糠蛋白酶解产物中获取了ACE抑制剂。

Study on ACE Inhibitor in Hydrolyzates of Rice Bran Protein

Objective To obtain angiotensin-converting-enzyme (ACE) inhibitor from the hydrolyzates of rice bran protein.Methods The deposition method of adjusting isoelectric point was adapted to get rice bran protein. The protein was hydrolyzed with pepsin and trypsin successively. The hydrolyzed products were separated to many groups by gel chromatography and ACE inhibitor activity of each group was tested. One group with high inhibitor activity was further separated and purified by ion exchange chromatography.Results The molecular weight of ACE inhibitor peptide obtained was 307.1 and the isoelectric point was 5-6 with the IC_ 50 being 0.061 mg/ml. Its bioactivity was stable in the hydrolyzates digested with pepsin and trypsin.Conclusion ACE inhibitor was obtained from the hydrolyzates of rice bran protein.