School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China.
College of Food Science and Engineering, Yangzhou University, Yangzhou 225127, China.
Food Chem. 2021 Dec 1;364:130432. doi: 10.1016/j.foodchem.2021.130432. Epub 2021 Jun 21.
Our previous studies had shown that watermelon seed antioxidant peptides (WSAPs: P1-P5) possessed good activities. However, the structure-activity relationship of P1 is still unclear. Quantum chemistry and molecular docking were used to investigate the antioxidant mechanism of P1. The active site of P1 is located at CH on Arg. P1 can bind to DPPH/ABTS through hydrogen bond and hydrophobic interaction. Compared with P2-P4, P1 has the strongest antioxidant capacity. The molecular simulation showed that P1 could enhance the stability of Keap1 by interacting with Asn382, Arg380 and Tyr 334 in the active sites. Compared with the model group, the expression of Keap1 was down-regulated (p < 0.05), while the expression of Nrf2 and HO-1 was up-regulated (p < 0.05) after P1 treatment. P1 has the potential ability to activate the signaling pathway Keap1-Nrf2 and improve the antioxidant defense system. This study provides a new perspective for the rational design and mechanism of antioxidant peptides.
我们之前的研究表明，西瓜籽抗氧化肽（WSAPs：P1-P5）具有良好的活性。然而，P1 的构效关系尚不清楚。本研究采用量子化学和分子对接方法研究 P1 的抗氧化机制。P1 的活性位点位于精氨酸上的 CH。P1 可以通过氢键和疏水相互作用与 DPPH/ABTS 结合。与 P2-P4 相比，P1 具有最强的抗氧化能力。分子模拟表明，P1 可以通过与活性位点中的 Asn382、Arg380 和 Tyr334 相互作用来增强 Keap1 的稳定性。与模型组相比，P1 处理后 Keap1 的表达下调（p<0.05），而 Nrf2 和 HO-1 的表达上调（p<0.05）。P1 具有激活 Keap1-Nrf2 信号通路和提高抗氧化防御系统的潜在能力。本研究为抗氧化肽的合理设计和机制提供了新的视角。
