Antimicrobial peptide databases and protein analysis software were used to optimize the design of bovine lactoferricin-derived peptide (LfcinBD), based on knowledge of the relationship between the structure and function of antimicrobial peptides. The designed lactoferricin-derived peptide gene fragment was inserted into a pPIC9K plasmid to construct a recombinant expression vector. After linearization, Pichia pastoris GS115 cells were transfected by electroporation, and expression was induced with methanol. Isolation, purification, and activity measurements of fermentation supernatants were performed. SDS-PAGE analysis confirmed efficient expression of the target protein. Comparing the optimally designed LfcinBD derivative with natural LfcinB, it was confirmed that the derived peptide had stronger bacteriostatic activity against Staphylococcus aureus. This study indicated that the LfcinB in which amino acid 10 and 14 were replaced with Trp has better antibacterial activity. This work lays the foundation for further exploration to improve the biological activities of LfcinBD.
