ABSTRACT Peptic hydrolysates were prepared by digesting the cutlassfish muscle protein using pepsin for 1, 3, and 6 h, and their inhibitory activity against angiotensin-I converting enzyme (ACE) was studied. The ACE-inhibitory effect of the peptic hydrolysate of cutlassfish muscle generated at the 3 h time point exhibited the strongest activity. After identifying the optimal hydrolysate, the active peptide was isolated by ultrafiltration, gel permeation, and high performance liquid chromatography (HPLC). The resulting purified peptide was characterized using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF/TOF MS/MS) and was identified to be a 496.44 Da pentapeptide (Phe-Ser-Gly-Gly-Glu). The ACE-inhibitory activity of the active peptide exhibited an IC50 value of 0.033 ± 0.003 mg/ml. A molecular docking program was used to simulate the interaction between the peptide and ACE, which revealed that the inhibitory effect was mainly due to the hydrogen bonds between ACE and the peptide. Based on the ACE-inhibitory properties and the molecular docking study of the resulting active peptide, we demonstrated an increase in nitric oxide (NO) production in a dose-dependent manner. In conclusion, cutlassfish protein hydrolysate and the resulting active peptide could be used as active ingredients in functional food as anti-hypertensive agents.

中文翻译：

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血管紧张素-I 转化酶 (ACE) 抑制活性的潜在前体和来自鱿鱼肌肉消化性水解产物的肽的结构特性

摘要 通过使用胃蛋白酶消化鱿鱼肌肉蛋白 1、3 和 6 小时制备了消化水解物，并研究了它们对血管紧张素 I 转化酶 (ACE) 的抑制活性。在 3 小时时间点产生的墨鱼肌肉消化性水解物的 ACE 抑制作用表现出最强的活性。在确定最佳水解产物后，通过超滤、凝胶渗透和高效液相色谱 (HPLC) 分离活性肽。使用基质辅助激光解吸电离飞行时间质谱 (MALDI-TOF/TOF MS/MS) 对所得纯化肽进行表征，并鉴定为 496.44 Da 五肽 (Phe-Ser-Gly-Gly-Glu)。活性肽的 ACE 抑制活性的 IC50 值为 0.033 ± 0.003 mg/ml。分子对接程序用于模拟肽与ACE之间的相互作用，表明抑制作用主要是由于ACE与肽之间的氢键。基于 ACE 抑制特性和所得活性肽的分子对接研究，我们证明了一氧化氮 (NO) 的产生以剂量依赖性方式增加。综上所述，鱿鱼蛋白水解物及其活性肽可作为抗高血压剂的功能性食品中的活性成分。我们证明了一氧化氮 (NO) 的产生以剂量依赖性方式增加。综上所述，鱿鱼蛋白水解物及其活性肽可作为抗高血压剂的功能性食品中的活性成分。我们证明了一氧化氮 (NO) 的产生以剂量依赖性方式增加。综上所述，鱿鱼蛋白水解物及其活性肽可作为抗高血压剂的功能性食品中的活性成分。