A novel antimicrobial peptide WBp-1 from wheat bran: Purification, characterization and antibacterial potential against Listeria monocytogenes.

This study introduces a novel antimicrobial peptide (AMP), WBp-1, isolated from wheat bran and purified via reversed-phase high-performance liquid chromatography. The amino acid sequence, determined as IITGASSGIGKAIAKHFI by LC-MS/MS, was composed predominantly of alkaline and hydrophobic residues. WBp-1 was predicted to be a stable, hydrophobic, cationic peptide with an α-helical structure. Moreover, it displayed significant antibacterial efficacy against Listeria monocytogenes, with a minimum inhibitory concentration of 150 μg/mL. Further mechanistic studies suggest that WBp-1 exerts its bactericidal activity by disrupting cell membrane integrity, impeding peptidoglycan synthesis by binding to penicillin-binding protein 4 via hydrogen bonding, increasing cell permeability, altering membrane potential and fluidity, and altering surface hydrophobicity. Interestingly, WBp-1 showed minimal hemolytic activity and cytotoxicity against LO2 cells, even at 16× MIC. These findings highlight the strong potential of WBp-1 as a novel antibacterial agent and food preservative against Listeria monocytogenes.