乳链菌肽的抑菌机制

乳链菌肽(Nisin)是由乳酸乳球菌的某些菌株产生的1种羊毛硫细菌素。因其高效的抗菌性及对人体的低毒性而被广泛应用于食品防腐。孔道形成是Nisin抑菌作用的主要方式。Nisin可通过其带正电荷肽的C-端与带负电荷的磷脂之间的静电引力在细胞质膜上形成孔道,也能通过lipid Ⅱ的锚定作用形成lipid Ⅱ介导的孔道,同时Nisin与lipid Ⅱ结合抑制肽聚糖生物合成。Nisin对大肠杆菌的抑菌机制是对高盐敏感,而其对葡萄球菌的抑菌机制是对高盐不敏感。文章综述了Nisin的抑菌机制。

Antibacterial Mechanism of Nisin

Nisin is a kind of lantibiotis produced by certain strains of Lactococcus Lactis. It has been employed as a food preservative as it has a high antibacterial activity with a relatively low toxicity for human. Pore formation is considered the primary mode of antimicrobial action of nisin. Nisin forms wedge-like pore in the membrane by electrostatic interaction between the positively charged C-terminus of the peptide and anionic phospholipids. Nisin can also form lipid II-mediated pore via a targeted mechanism by using lipid II,the bactoprenol-bound precursor of the bacterial cell wall,as a docking molecule. Another consequence of binding with lipid II is the inhibition of peptidoglycan biosynthesis. Nisin utilizes two distinct mechanisms of antibacterial activity:a high-salt-sensitive mechanism for Escherichia coli and a high-salt-insensitive mechanism for Staphylococcus aureus. Antibacterial mechanism of nisin was reviewed comprehensively in this article.