中文摘要：

采用类蛋白反应修饰海地瓜体壁蛋白酶解物，制得修饰肽的血管紧张素转换酶（ ACE）抑制活性与原酶解液的活性相比显著提高；模拟消化实验结果表明，修饰肽与胃肠蛋白酶作用后可增强其降压活性；细胞毒性实验结果表明，样品浓度在低于10 mg/mL时对犬肾细胞（ MDCK）无毒性，且低浓度可以促进细胞生长.采用超滤、Sephadex G-15凝胶柱层析和RP-HPLC等分离技术纯化修饰产物，得到高活性ACE抑制肽（ IC50值为3.67μmol/L），序列结构为NQNFVQYTTNT.紫外光谱分析结果表明，修饰肽与ACE 结合可引起吸光度变化.用SYBYL软件对抑制肽与ACE活性位点进行模拟对接，发现该抑制肽能与ACE很好地结合.

英文摘要：

The effect of modification by plastein reaction on the angiotensin converting enzyme（ ACE） inhibi-tory activity of Acaudina molpadioides hydrolysates and its peptides was researched to show that the ACE inhib-itory activity of modified peptide decreased definitely, compared with the activity of original hydrolysates. The stability of the modified peptides to simulated gastrointestinal digestion was tested in vitro. The result showed that the ACE inhibitory activities of the peptides could be enhanced by digestive enzyme. Toxicity test showed no toxic to the MDCK cells while concentration was less than 10 mg/mL, and low concentration could promote the cells’ growth. A novel ACE inhibitory peptide was isolated from modified product using different methods including ultrafiltration, Sephadex G-15 gel filtration and RP-HPLC. The purified ACE inhibitory peptide was sequenced as NQNFVQYTTNT with an IC50 value of 3. 67μmol/L. The accurate sites of ACE that the peptide bind to were determined through the computer assisted software SYBYL, and UV spectra analysis proved that some changes could be observed in the binding of ACE and peptides.