Application of non-thermal treatment to proteins prior to enzymatic hydrolysis can facilitate the release of novel bioactive peptides (BPs) with unique biological activities. In this study, lupin protein isolate was pre-treated with ultrasound and hydrolysed using alcalase and flavourzyme to produce alcalase hydrolysate (ACT) and flavourzyme hydrolysate (FCT). These hydrolysates were fractionated into 1, 5, and 10 kDa molecular weight fractions using a membrane ultrafiltration technique. The in vitro angiotensin-converting enzyme (ACE) studies revealed that unfractionated ACT (IC₅₀ = 3.21 mg mL⁻¹) and FCT (IC₅₀ = 3.32 mg mL⁻¹) were more active inhibitors of ACE in comparison to their ultrafiltrated fractions with IC₅₀ values ranging from 6.09 to 7.45 mg mL⁻¹. Molecular docking analysis predicted three unique peptides from ACT (AIPPGIPY, SVPGCT, and QGAGG) and FCT (AIPINNPGKL, SGNQGP, and PPGIP) as potential ACE inhibitors. Thus, unique BPs with ACE inhibitory effects might be generated from ultrasonicated lupin protein.

在酶水解前对蛋白质进行非热处理可以促进具有独特生物活性的新型生物活性肽 (BP) 的释放。在这项研究中，羽扇豆分离蛋白经过超声波预处理，并使用碱性蛋白酶和风味酶水解，产生碱性蛋白酶水解物 (ACT) 和风味酶水解物 (FCT)。使用膜超滤技术将这些水解产物分成 1、5 和 10 kDa 分子量级分。体外血管紧张素转换酶 (ACE)研究表明，未分级 ACT (IC ₅₀  = 3.21 mg mL ^-1 ) 和 FCT (IC ₅₀  = 3.32 mg mL ^-1) 与其超滤级分相比，是更活跃的 ACE 抑制剂，IC ₅₀值范围为 6.09 至 7.45 mg mL ^-1。分子对接分析预测来自 ACT（AIPPGIPY、SVPGCT 和 QGAGG）和 FCT（AIPINNPGKL、SGNQGP 和 PPGIP）的三种独特肽是潜在的 ACE 抑制剂。因此，超声处理的羽扇豆蛋白可能会产生具有 ACE 抑制作用的独特 BP。