Structural Design of Bovine Lactoferricin-derived Peptide and Its Activity Assay after Expressed in Pichia pastoris

In this study, the structure of bovine lactoferricin peptide-derived (LfcinBD) was optimized by antimicrobial peptide database and bioinformatics tools, and the gene fragment of the LfcinB-W4 was expressed in Pichia pastoris GS115.The results of fermentation experiments showed that when the methanol induction concentration was 2.5% and the fermentation time was 96 h, the fermentation supernatant had a strong inhibitory effect on Staphylococcus aureus and Salmonella, and its effect was compared with the antibacterial effect of 50 mg/mL ampicillin. After the fermentation supernatant was freeze-dried and concentrated, the bacteriostatic effect of the 10-fold concentrate was 2.5 times that of the same volume of 50 mg/mL ampicillin. LFcinB-W4 with a relative molecular mass of about 3.2 kDa was detected by Tricine-SDS-PAGE. In this experiment, bio-informatics tools were designed to obtain derived peptides with higher antibacterial activity than LFcinB, which laid a foundation for further analysis of the relationship between bovine lactoferrin peptide function and structure.