Human health can be damaged by free radicals, and antioxidant peptides are excellent radical scavengers. Antioxidant tripeptides data set based on 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulofnic acid) (ABTS) assay was created, 9 types of descriptors were integrated and 4 quantitative structure–activity relationship (QSAR) models were constructed in this study. Several structural factors influencing the activity of antioxidant tripeptides and the dominant amino acids at each position of tripeptides were revealed by the optimal model. Ten food-derived tripeptides with higher activity were selected for synthesis and activity determination. Molecular docking results demonstrated that these tripeptides were stably bound to the Keap1 receptor, further elucidating the antioxidant mechanism. It was known from the simulation of gastrointestinal digestion experiments that the model results possessed a guiding effect on the selection of proteins with high antioxidant activity . The performance of the model was proved to be robust after validation.
Chaonan Sun,Yingnan Liu,Shiyang Liu,Ying Bu,Wenhui Zhu,Xuepeng Li
Fish sauce, derived from fermented fish, exhibits a notable antioxidant effect after a six-month fermentation process, and we propose that potential antioxidant peptides were present in the fish sauce. We isolated, purified, and identified potential bioactive antioxidant peptides by using fish sauce fermented for 6 months. Additionally, molecular simulation was employed to investigate the antioxidant action mechanism of these bioactive peptides. The molecular docking results revealed that FS4-1 (MHQLSKK), FS4-2 (VLDNSPER), FS4-3 (MNPPAASIK), FS6-1(VLKQAAAGR), and FS6-2 (SPDVSPRR), could dock with the Keap1 receptor. The primary force (Van der Waals' force and hydrogen bonds) and key sites (GLY509 and ALA510) of Keap1 binding to peptides were determined. The active center was located in the side chain of amino acid Met at positions C7H78 and C7H79. We here identified antioxidant peptides in fish sauce and revealed the antioxidant mechanism through molecular simulations.