Antimicrobial peptides are being explored for use as food preservatives to prevent foodborne diseases. In this study, bioinformatics tools were used to screen potential antimicrobial amino acid sequences from the whey acidic protein (WAP) of large yellow croaker (Larimichthys crocea). A novel antimicrobial peptide, designated as LCWAP, was identified and its antimicrobial effect and mechanism of action on Staphylococcus aureus was explored. The minimal inhibitory concentration (MIC) of LCWAP on S. aureus was 15.6 μg/mL. Transmission electron microscopy and laser confocal microscopy revealed that LCWAP kills bacteria by aggregating on the cell surface, destroying the integrity of bacterial cell membrane and resulting in the leakage of intracellular solutes. Moreover, peptide LCWAP inhibit biofilm formation, at concentrations of 1–1/16 × MIC, with biofilm formation found to decrease by 94.3%–13.7% upon LCWAP treatment. The ability of peptide LCWAP to bind bacteria DNA was revealed using electrophoresis analysis and ultraviolet absorption spectroscopy, with peptide LCWAP/DNA weight ratios of 125/1, and 17.3% decrease in the absorption peak of LCWAP. Furthermore, LCWAP had no cytotoxic effects on normal human hepatocytes, although it had strong inhibitory effect on S. aureus growth in milk.

人们正在探索将抗菌肽用作食品防腐剂，以预防食源性疾病。在这项研究中，使用生物信息学工具从大型黄花鱼（Larimichthys crocea）的乳清酸性蛋白（WAP）中筛选潜在的抗菌氨基酸序列。确定了一种新型的抗菌肽，称为LCWAP，并探讨了其对金黄色葡萄球菌的抗菌作用和作用机理。LCWAP对金黄色葡萄球菌的最小抑制浓度（MIC）为15.6μg/ mL。透射电子显微镜和激光共聚焦显微镜显示，LCWAP通过聚集在细胞表面杀死细菌，破坏细菌细胞膜的完整性并导致细胞内溶质的泄漏。此外，肽LCWAP抑制生物膜形成，浓度为1-1 / 16×MIC，经LCWAP处理后，生物膜形成减少了94.3％–13.7％。肽LCWAP结合细菌DNA的能力通过电泳分析和紫外吸收光谱法得以揭示，肽LCWAP / DNA的重量比为125/1，LCWAP的吸收峰降低了17.3％。此外，LCWAP尽管对牛奶中的金黄色葡萄球菌生长具有很强的抑制作用，但对正常人的肝细胞没有细胞毒性作用。