Identification and molecular mechanism of novel antioxidant peptides from milk tofu cheese: Peptidomics, molecular dynamics, and cell experiments

Yuzhu Wang; Ziqi Xu; Daodian Wang; Wentao Zheng; Yufang Li; Yue Wang; Zhenzhu Li; Guangqiang Wei; Aixiang Huang

doi:10.1016/j.foodchem.2025.145403

Identification and molecular mechanism of novel antioxidant peptides from milk tofu cheese: Peptidomics, molecular dynamics, and cell experiments

Food Chem. 2025 Jul 3;492(Pt 2):145403. doi: 10.1016/j.foodchem.2025.145403. Online ahead of print.

Authors

Yuzhu Wang¹, Ziqi Xu¹, Daodian Wang², Wentao Zheng¹, Yufang Li¹, Yue Wang¹, Zhenzhu Li¹, Guangqiang Wei³, Aixiang Huang⁴

Affiliations

¹ College of Food Science & Technology, Yunnan Agricultural University, Kunming 650201, Yunnan, China.
² College of Food Science & Technology, Yunnan Agricultural University, Kunming 650201, Yunnan, China; Sericulture and Apiculture Research Institute, Yunnan Academy of Agricultural Sciences, Mengzi 661101, Yunnan, China.
³ College of Food Science & Technology, Yunnan Agricultural University, Kunming 650201, Yunnan, China. Electronic address: 1134131384@qq.com.
⁴ College of Food Science & Technology, Yunnan Agricultural University, Kunming 650201, Yunnan, China. Electronic address: aixianghuang@126.com.

PMID: 40651143
DOI: 10.1016/j.foodchem.2025.145403

Abstract

This study investigated the antioxidative and cytoprotective activity of antioxidant peptides from acid-cured milk tofu cheese (MTFC) and preliminarily explored their potential antioxidant mechanism. Of the 312 peptides identified in MTFC by LC-MS/MS, a novel antioxidant peptide NQFLPYPYY (NY9) exhibited significant ABTS radical scavenging activity of IC₅₀ = 11.06 μmol/L, as well as excellent thermal and pH stability. Molecular docking analyses revealed that NY9 interacts with key active sites of Keap1, including Leu557, Leu365, Val465, Thr560, and Gly464, through hydrogen bonding and hydrophobic interactions. Furthermore, molecular dynamics simulations confirmed the stable binding of NY9 to Keap1. Cell experiments showed that NY9 exhibited notable cellular antioxidant activity, effectively protecting HepG2 cells from oxidative damage by decreasing intracellular reactive oxygen species and malondialdehyde levels, and increasing catalase and glutathione peroxidase activities. This study provides a theoretical basis for the high-value utilization of MTFC and the development of highly active antioxidant peptides.

Keywords: Antioxidant peptides; Cytoprotective ability; Keap1-Nrf2 pathway; Milk tofu cheese; Molecular dynamics simulation.