Screening and identification of soybean antioxidant peptides using Fe3O4-Modified carbon fibers

This study presents an effective strategy for the screening and enrichment of antioxidant peptides from soybean protein using Fe 3 O 4 -modified carbon fibers with abundant metal-binding sites. Successful material synthesis was confirmed via scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) and X-ray diffraction (XRD) analyses. Under optimized adsorption conditions, an adsorption ratio of 22.95% was achieved, and the resulting peptide fractions displayed significantly enhanced antioxidant activity. Through integrated Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) analysis, bioactivity prediction tools, four high-activity peptides were identified: KFFFR, RYFPF, FLWLR, and WERLY. Among them, WERLY exhibited the most potent antioxidant properties, with IC 50 values of 0.437, 0.638, 0.182, and 0.583 mg/mL for ABTS, superoxide, hydroxyl radical scavenging, and ferrous ion chelation, respectively. Notably, its hydroxyl radical scavenging capacity was comparable to that of the positive control, glutathione. Cellular assays further demonstrated that WERLY protected HepG2 cells against oxidative damage, as evidenced by increased activities of Catalase (CAT), Superoxide Dismutase (SOD), and Glutathione Peroxidase (GSH-Px), along with reduced Malondialdehyde (MDA) levels. Molecular docking and molecular dynamics simulations suggested that WERLY may interact with the Keap1 protein, providing supportive insight into its potential involvement in cellular antioxidant defense mechanisms. However, the precise molecular mechanism requires further validation. Overall, this study demonstrates that Fe 3 O 4 -modified carbon fibers provide an efficient platform for screening antioxidant peptides from soybean protein, offering a promising strategy for the development of functional bioactive peptides.