College of Food Science, Northeast Agricultural University, Harbin 150030, China.
J Agric Food Chem. 2023 Aug 23;71(33):12462-12473. doi: 10.1021/acs.jafc.2c09148. Epub 2023 Aug 14.
Inhibition of angiotensin I-converting enzyme (ACE) activity is an effective way to treat hypertension. In the present study, the ability to produce ACE-inhibitory peptides during fermentation of skimmed milk by the M3 strain was evaluated, and the inhibitory mechanism and stability were studied by bioinformatics analysis. The results showed that the ACE inhibition activity of fermented milk was 71.94 ± 1.39%. After digestion with gastric juice and pancreatic juice, the ACE inhibitory activities of the fermented milk were 78.40 ± 1.93 and 74.96 ± 1.73%, respectively. After the fermented milk was purified using ultrafiltration and gel chromatography, 11 peptides from milk proteins were identified and sequenced by Nano LC-MS/MS. Molecular docking displayed that peptide PWIQPK had a high affinity, with ACE showing a binding energy of -6.10 kcal/mol. Hydrogen bonds were formed between PWIQPK and Glu384 in the S1 active pocket of ACE and Asp358. In addition, van der Waals forces were observed. proteolysis suggested that PWIQPK could resist the digestion of pepsin and trypsin, indicating that it is relatively stable in the digestive tract. All results indicate that milk fermented by M3 has the potential to be used as a functional food having antihypertensive effects.
血管紧张素转化酶（ACE）活性抑制是治疗高血压的有效方法。本研究评估了 M3 菌株在脱脂乳发酵过程中产生 ACE 抑制肽的能力，并通过生物信息学分析研究了其抑制机制和稳定性。结果表明，发酵乳的 ACE 抑制活性为 71.94±1.39%。经过胃蛋白酶和胰蛋白酶消化后，发酵乳的 ACE 抑制活性分别为 78.40±1.93%和 74.96±1.73%。发酵乳经超滤和凝胶色谱纯化后，通过纳升液相色谱-串联质谱（Nano LC-MS/MS）鉴定并测序了 11 种乳蛋白来源的肽。分子对接显示，肽 PWIQPK 与 ACE 具有高亲和力，结合能为-6.10 kcal/mol。PWIQPK 与 ACE 的 S1 活性口袋中的 Glu384 和 Asp358 形成氢键，此外还观察到范德华力。酶解表明 PWIQPK 能够抵抗胃蛋白酶和胰蛋白酶的消化，表明其在消化道中相对稳定。所有结果均表明，M3 发酵的牛奶具有作为具有降血压作用的功能性食品的潜力。
