深海鲑鱼皮来源ACE抑制肽的分离及鉴定

为了考察海洋胶原低聚肽中ACE抑制肽的活性和结构，本文以深海鲑鱼皮为原料，采用两步酶解法制备出海洋胶原低聚肽，在对其分子量分布进行分析的基础上，测定了其血管紧张素转化酶（ACE）抑制活性。结果表明，海洋胶原低聚肽中分子量小于1000 u的组分高达90.79%，主要分布在132~576 u范围内，其ACE抑制活性的IC50为1.18±0.12 mg/mL。然后利用反相高效液相色谱（RP-HPLC）对海洋胶原低聚肽进行分离纯化，收集11个组分峰，对其ACE抑制活性进行了测定。结果表明，有7个组分的ACE抑制活性比海洋胶原低聚肽高。最后利用Q-TOF质谱仪对收集的11个组分进行了结构鉴定，并对鉴定出的15个肽段进行了ACE抑制活性测定。结果表明，15个肽段均有一定的ACE抑制活性，其中Ala-Pro（AP）、Val-Arg（VR）、Gly-Arg（GR）的ACE抑制率比海洋胶原低聚肽高，IC50值分别为0.07±0.01 mg/mL、0.35±0.03 mg/mL、0.92±0.85 mg/mL，活性大约是海洋胶原低聚肽的16.86、3.37、1.28倍，是具有较高ACE抑制活性的肽段。
To investigate the activity and structure of angiotensin-converting enzyme (ACE) inhibitory peptides derived from marine collagen oligopeptides (MCOPs), MCOPs were prepared from deep-sea salmon skin by two-step enzymolysis. Based on analysis of the molecular weight distribution, the ACE inhibitory activity of MCOP was determined. The results showed that the components with a molecular weight of less than 1000 u in MCOP accounted for up to 90.79% of all proteins and were mainly distributed in the range of 132~576 u, and the corresponding IC50 for ACE activity was 1.18 ± 0.12 mg/mL. Subsequently, MCOPs were separated and purified by reverse-phase high performance liquid chromatography (RP-HPLC) and the ACE inhibitory activity of 11 fractions was measured. Seven fractions had a higher ACE inhibitory activity than the total MCOP mixture. Finally, structural identification of peptides in the 11 fractions was performed on a quadrupole time-of-flight (Q-TOF) mass spectrometer and the ACE inhibitory activity of the 15 identified peptides was determined. The results indicated that all peptides exhibited ACE inhibitory activity and Ala-Pro (AP), Val-Arg (VR), and Gly-Arg (GR) showed stronger activities than the total MCOP mixture. The IC50 values of the three peptides were 0.07 ± 0.01 mg/mL, 0.35 ± 0.03 mg/mL, and 0.92 ± 0.85 mg/mL, respectively. Their ACE inhibitory activities were 16.86, 3.37, and 1.28 times the inhibitory activity of the MCOP mixture, respectively. Therefore, AP, VR, and GR are peptides with potent ACE inhibitory activity.