Abstract Nisin, the only antimicrobial peptide that has GRAS (generally considered as safe) status from both WHO and FDA, has the potential to become an important natural antibiotic as bacteria become more resistant to traditional antibiotics. Many studies have focused on how modification of nisin affects antimicrobial activity. In this study, nisin and chitosan were crosslinked using genipin to modify the N-terminal of nisin. The antimicrobial experiments were carried out on Staphylococcus aureus ATCC 6538. The results showed that nisin still retained antimicrobial activity after modification. When the crosslinking ratio of nisin to chitosan increased to 200: 1, MIC decreased from 48 μg/ml to 40 μg/ml. Less chitosan increased local number density and antimicrobial activity of nisin. When the local number density was high, adjacent peptides could cooperatively penetrate into the lipid membrane. The results of this study may help to better understand the antimicrobial mechanism and provide suggestions for the further modification of nisin.

中文翻译：

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N端修饰对乳酸链球菌肽抗菌活性的影响

摘要 Nisin 是唯一一种被 WHO 和 FDA 授予 GRAS（通常被认为是安全的）状态的抗菌肽，随着细菌对传统抗生素的耐药性增强，它有可能成为一种重要的天然抗生素。许多研究都集中在乳链菌肽的修饰如何影响抗菌活性上。在这项研究中，乳链菌肽和壳聚糖使用京尼平进行交联以修饰乳链菌肽的 N 端。对金黄色葡萄球菌ATCC 6538进行了抑菌实验，结果表明，经修饰后的乳酸链球菌素仍保留了抗菌活性。当乳链菌肽与壳聚糖的交联比增加到 200:1 时，MIC 从 48 μg/ml 下降到 40 μg/ml。较少的壳聚糖增加了乳酸链球菌素的局部数密度和抗菌活性。当局部数密度高时，相邻的肽可以协同渗透到脂质膜中。本研究的结果可能有助于更好地了解抗菌机制，并为进一步修饰乳酸链球菌素提供建议。