Bioactive peptides profiles from pepsin hydrolysis of ovomucin: Sequence identification and antibacterial activity...

Ovomucin (OVM), a viscous glycoprotein, is a by-product of industrial egg white lysozyme production. Although OVM has shown potential against the gastric pathogen Helicobacter pylori, systematic studies on its pepsin-derived peptides remain limited. In this study, OVM was subjected to pepsin at pH 3.0 to obtain a mixed peptide fraction (POVMp) that retains stability under gastric conditions. The peptide sequences were identified via mass spectrometry, followed by in silico property prediction, and the inhibitory activity of the hydrolysate against H.pylori was evaluated. A total of 121 POVMp peptides with molecular weights ranging from 1 to 3 kDa were identified. Sequence-based analysis indicated that POVMp consists mainly of cationic peptides with both membrane- and protein-amphiphilic characteristics. The minimum inhibitory concentration (MIC) of POVMp against H.pylori was 125 μg/mL. Mechanistically, POVMp depolarized the H.pylori cell membrane and induced morphological conversion, and compromised membrane integrity. Transcriptomic sequencing further revealed that POVMp downregulated genes associated with energy metabolism and flagellar synthesis. These changes lead to a reduction in bacterial viability and motility. Consistently, POVMp significantly inhibited biofilm formation and motility, and reduced intracellular ATP levels (p < 0.05) as confirmed by functional assays. These findings position POVMp as a food-grade bioactive ingredient that may be used in functional foods for adjunctive or prophylactic support against H.pylori. This study also provides a strategy for the value-added utilization of an egg industry by-product.