Our previous study identified five peptides Leu-Tyr (LY), Pro-Tyr (PY), Tyr-Gln (YQ), Ala-Pro-Ser-Tyr (APSY), and Arg-Gly-Gly-Tyr (RGGY) from wheat gluten. However, the mechanism of antioxidant action and structure-function relationship of these five peptides were still unclear. In this study, we found that five peptides induced by AAPH in human embryonic kidney cells (HEK-293) suppressed the intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) production. Moreover, they also upregulated the antioxidant activity-related enzymes (SOD, CAT and GSH-Px) and GSH activities. Additionally, five peptides treatment decreased Keap1 protein level and increased Nrf2 and HO-1proteins levels. It was concluded that five peptides showed promise in activating the Keap1-Nrf2-HO-1 signaling pathway and enhancing the antioxidant defense system. Quantum chemical calculation and molecular docking technologies were used to explore the action mechanism of five wheat peptides. Five antioxidant peptides were able to effectively bind Keap1, and the peptides predominantly formed hydrogen and π bonds during their binding with the active pocket region of Keap1.

中文翻译：

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5种小麦麸质抗氧化肽对细胞氧化应激损伤的抑制作用及作用机制

我们之前的研究从其中鉴定出五种肽 Leu-Tyr (LY)、Pro-Tyr (PY)、Tyr-Gln (YQ)、Ala-Pro-Ser-Tyr (APSY) 和 Arg-Gly-Gly-Tyr (RGGY)小麦面筋。然而，这五种肽的抗氧化作用机制和结构功能关系仍不清楚。在这项研究中，我们发现人胚胎肾细胞 (HEK-293) 中 AAPH 诱导的五种肽抑制细胞内活性氧 (ROS) 和丙二醛 (MDA) 的产生。此外，它们还上调了抗氧化活性相关酶（SOD、CAT 和 GSH-Px）和 GSH 活性。此外，五肽治疗降低了 Keap1 蛋白水平，增加了 Nrf2 和 HO-1 蛋白水平。结论是，五种肽在激活 Keap1-Nrf2-HO-1 信号通路和增强抗氧化防御系统方面表现出良好的前景。利用量子化学计算和分子对接技术探讨了5种小麦肽的作用机制。 5种抗氧化肽能够有效结合Keap1，并且这些肽在与Keap1活性口袋区域结合时主要形成氢键和π键。