Angiotensin-converting enzyme (ACE), consisting of N-domain and C-domain, is a key regulator of blood pressure. The use of cACE-specific inhibitors helps minimize side effects in clinical applications. Legumes are a good source of proteins containing ACE inhibitory peptides; however, no studies have reported the identification of cACE-specific inhibitory peptides from Fabaceae. In this study, thermal hydrolysates from seeds, sprouts, pods, seedlings, and flowers of legumes were analyzed. Flowers of legumes exhibited a C-domain-preference ACE inhibition and anti-hypertensive effect in rats. Screening the legume peptide library identified a novel cACE inhibitory peptide, SJ-1. This study reported the first identification of cACE inhibitory peptide from Fabaceae foods. SJ-1, identified from the legume flowers, interacted with active site residues of cACE, leading to the inhibition of ACE activity, downregulation of bradykinin levels, and reduction of blood pressure. These findings also suggested the potential of legume proteins as a source of cACE inhibitory peptides.

中文翻译：

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豆科食品肽库中新型血管紧张素转换酶C结构域抑制肽的筛选及合理鉴定

血管紧张素转换酶（ACE）由N结构域和C结构域组成，是血压的关键调节因子。使用 cACE 特异性抑制剂有助于最大限度地减少临床应用中的副作用。豆类是含有 ACE 抑制肽的蛋白质的良好来源；然而，尚无研究报道从豆科植物中鉴定出 cACE 特异性抑制肽。在这项研究中，分析了豆科植物的种子、芽、豆荚、幼苗和花的热水解产物。豆科植物的花在大鼠中表现出 C 结构域优先的 ACE 抑制和抗高血压作用。筛选豆类肽库发现了一种新型 cACE 抑制肽 SJ-1。本研究首次从豆科食品中鉴定出 cACE 抑制肽。从豆科植物花中鉴定出的 SJ-1 与 cACE 活性位点残基相互作用，从而抑制 ACE 活性、下调缓激肽水平并降低血压。这些发现还表明豆类蛋白作为 cACE 抑制肽来源的潜力。