Naked oat globulin was hydrolyzed by alcalase, flavourzyme, pepsin, and trypsin in sequence. The hydrolysates (NOGH) were purified using gel chromatography, reversed-phase high performance liquid chromatography (RP-HPLC). Finally, fraction D7d with the highest ACE-inhibitory was subjected to liquid chromatography-mass spectrometry analysis and 14 peptides were identified. Of which, peptide SSYYPFK (890.4 Da) was chose to synthesize based on in silico analysis. The SSYYPFK demonstrated high ACE-inhibitory activity (IC50 : 91.82 µM) with competitive inhibition mode, and could effectively (P < 0.05) lower the systolic blood pressure and diastolic pressure of spontaneously hypertensive rats at the concentration of 100 to 150 mg/kg body weight. Molecular docking simulation demonstrated that SSYYPFK could bind with the active site S1 of ACE via short hydrogen bonds. It could remain the ACE-inhibitory activity after simulated gastrointestinal hydrolysis. Moreover, SSYYPFK showed acceptable renin and endothelin-1 suppressing capacity (47.59% and 27.88% at 1.5 mg/mL, respectively). These results indicated that SSYYPFK may have similar antihypertensive mechanism with captopril, and could be develop to natural antihypertensive products. PRACTICAL APPLICATION: One novel ACE-inhibitory peptide SSYYPFK (890.4 Da) was identified from naked oat globulin hydrolysates. It exhibited relatively high renin and intracellular endothelin-1 suppressing capacity, and could effectively (P < 0.05) lower the systolic blood pressure and diastolic pressure of spontaneously hypertensive rats. This peptide could be used as natural and safe nutraceuticals and/or functional ingredients.

中文翻译：

---

从裸燕麦球蛋白水解物中分离出新型 ACE 抑制肽的计算机方法：分子对接、体内抗高血压和对肾素和细胞内内皮素-1 的影响

裸燕麦球蛋白依次被碱性蛋白酶、风味酶、胃蛋白酶和胰蛋白酶水解。使用凝胶色谱法、反相高效液相色谱法 (RP-HPLC) 纯化水解产物 (NOGH)。最后，对具有最高 ACE 抑制作用的级分 D7d 进行液相色谱-质谱分析，并鉴定出 14 种肽。其中，选择肽SSYYPFK（890.4 Da）基于计算机分析进行合成。SSYYPFK 在竞争性抑制模式下表现出较高的 ACE 抑制活性（IC50：91.82 µM），并且在 100 至 150 mg/kg 体重的浓度下可以有效（P < 0.05）降低自发性高血压大鼠的收缩压和舒张压重量。分子对接模拟表明，SSYYPFK 可以通过短氢键与 ACE 的活性位点 S1 结合。经模拟胃肠道水解后仍能保持ACE抑制活性。此外，SSYYPFK 显示出可接受的肾素和内皮素-1 抑制能力（在 1.5 mg/mL 时分别为 47.59% 和 27.88%）。这些结果表明SSYYPFK可能具有与卡托普利相似的降压机制，可开​​发为天然降压产品。实际应用：从裸燕麦球蛋白水解产物中鉴定出一种新型 ACE 抑制肽 SSYYPFK（890.4 Da）。它表现出较高的肾素和细胞内内皮素-1抑制能力，并能有效（P < 0.05）降低自发性高血压大鼠的收缩压和舒张压。