Li Jun, Li Qian, Li Jingyun, Zhou Bei
State Key Laboratory of Reproductive Medicine, Department of Plastic & Consmetic Surgery, Nanjing Maternity and Child Health Hospital, Nanjing Medical University, Nanjing 210029, China.
Molecules. 2014 Sep 2;19(9):13587-602. doi: 10.3390/molecules190913587.
Jellyfish (Rhopilema esculentum) was hydrolyzed using alcalase, and two peptides with angiotensin-I-converting enzyme (ACE) inhibitory and antioxidant activities were purified by ultrafiltration and consecutive chromatographic methods. The amino acid sequences of the two peptides were identified as VKP (342 Da) and VKCFR (651 Da) by electrospray ionization tandem mass spectrometry. The IC50 values of ACE inhibitory activities of the two peptides were 1.3 μM and 34.5 μM, respectively. Molecular docking results suggested that VKP and VKCFR bind to ACE through coordinating with the active site Zn(II) atom. Free radical scavenging activity and protection against hydrogen peroxide (H2O2)-induced rat cerebral microvascular endothelial cell (RCMEC) injury were used to evaluate the antioxidant activities of the two peptides. As the results clearly showed that the peptides increased the superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-px) activities in RCMEC cells), it is proposed that the R. esculentum peptides exert significant antioxidant effects.
利用碱性蛋白酶对海蜇（黄斑海蜇）进行水解，并通过超滤和连续色谱法纯化出两种具有血管紧张素转换酶（ACE）抑制活性和抗氧化活性的肽。通过电喷雾电离串联质谱法鉴定出这两种肽的氨基酸序列分别为VKP（342 Da）和VKCFR（651 Da）。这两种肽的ACE抑制活性的IC50值分别为1.3 μM和34.5 μM。分子对接结果表明，VKP和VKCFR通过与活性位点的Zn（II）原子配位与ACE结合。采用自由基清除活性和对过氧化氢（H2O2）诱导的大鼠脑微血管内皮细胞（RCMEC）损伤的保护作用来评估这两种肽的抗氧化活性。结果清楚地表明，这些肽增加了RCMEC细胞中的超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和谷胱甘肽过氧化物酶（GSH-px）活性，因此提出黄斑海蜇肽具有显著的抗氧化作用。
