Wang Peng, Song Xuemei, Liang Qi
Functional Dairy Products Engineering Laboratory of Gansu Province, College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, China.
Foods. 2024 Sep 19;13(18):2970. doi: 10.3390/foods13182970.
The bioactive peptides derived from yak milk cheese exhibited cholesterol-lowering properties. However, there was limited research on their inhibitory effects on cholesterol esterase (CE) and elucidation of their potential inhibitory mechanisms. In this study, we identified CE-inhibiting peptides through virtual screening and in vitro assays. Additionally, molecular docking and molecular dynamics studies were conducted to explore the mechanisms. The results indicated that peptides RK7 (RPKHPIK), KQ7 (KVLPVPQ), QP13 (QEPVLGPVRGPFP), TL9 (TPVVVPPFL), VN10 (VYPFPGPIPN), LQ10 (LPPTVMFPPQ), and SN12 (SLVYPFPGPIPN) possessed molecular weights of less than 1.5 kDa and a high proportion of hydrophobic amino acids, demonstrating notable inhibitory effects on CE. Molecular docking and dynamics revealed that peptides RK7, KQ7, QP13, and VN10 bound to key amino acid residues Arg423, His435, and Ser422 of CE through hydrogen bonds, hydrophobic interactions, salt bridges, and π-π stacking, occupying the substrate-binding site and exerting inhibitory effects on CE. The four peptides were further synthesized to verify their CE-inhibitory effects in vitro. RK7, KQ7, QP13, and VN10 exhibited inhibitory activity on CE with IC values of 8.16 × 10 mol/L, 8.10 × 10 mol/L, 4.63 × 10 mol/L, and 7.97 × 10 mol/L; RK7, KQ7, QP13, and VN10 were effective in inhibiting CE after simulated gastrointestinal digestion, especially with a significant increase in the inhibitory activity of KQ7 and RK7, respectively. Our findings suggested that bioactive peptides from yak milk cheese represented a novel class of potential CE inhibitors.
源自牦牛奶酪的生物活性肽具有降胆固醇特性。然而，关于它们对胆固醇酯酶（CE）的抑制作用及其潜在抑制机制的研究有限。在本研究中，我们通过虚拟筛选和体外试验鉴定了CE抑制肽。此外，还进行了分子对接和分子动力学研究以探索其机制。结果表明，肽RK7（RPKHPIK）、KQ7（KVLPVPQ）、QP13（QEPVLGPVRGPFP）、TL9（TPVVVPPFL）、VN10（VYPFPGPIPN）、LQ10（LPPTVMFPPQ）和SN12（SLVYPFPGPIPN）的分子量小于1.5 kDa且疏水氨基酸比例高，对CE表现出显著抑制作用。分子对接和动力学表明，肽RK7、KQ7、QP13和VN10通过氢键、疏水相互作用、盐桥和π-π堆积与CE的关键氨基酸残基Arg423、His435和Ser422结合，占据底物结合位点并对CE发挥抑制作用。进一步合成这四种肽以在体外验证其对CE的抑制作用。RK7、KQ7、QP13和VN10对CE表现出抑制活性，IC值分别为8.16×10⁻⁶ mol/L、8.10×10⁻⁶ mol/L、4.63×10⁻⁶ mol/L和7.97×10⁻⁶ mol/L；RK7、KQ7、QP13和VN10在模拟胃肠道消化后能有效抑制CE，尤其是KQ7和RK7的抑制活性分别显著增加。我们的研究结果表明，牦牛奶酪中的生物活性肽代表了一类新型的潜在CE抑制剂。
