Department of Molecular Genetics, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands.
ACS Synth Biol. 2020 Sep 18;9(9):2525-2536. doi: 10.1021/acssynbio.0c00308. Epub 2020 Aug 13.
Noncanonical amino acids form a highly diverse pool of building blocks that can render unique physicochemical properties to peptides and proteins. Here, four methionine analogues with unsaturated and varying side chain lengths were successfully incorporated at four different positions in nisin in through force feeding. This approach allows for residue-specific incorporation of methionine analogues into nisin to expand their structural diversity and alter their activity profiles. Moreover, the insertion of methionine analogues with biorthogonal chemical reactivity, e.g., azidohomoalanine and homopropargylglycine, provides the opportunity for chemical coupling to functional moieties and fluorescent probes as well as for intermolecular coupling of nisin variants. All resulting nisin conjugates retained antimicrobial activity, which substantiates the potential of this method as a tool to further study its localization and mode of action.
非天然氨基酸形成了一个高度多样化的构建块库，可赋予肽和蛋白质独特的物理化学性质。在这里，通过强制喂食，成功地将四种具有不饱和和不同侧链长度的甲硫氨酸类似物掺入到乳链菌肽中的四个不同位置。这种方法允许甲硫氨酸类似物在乳链菌肽中进行特定残基的掺入，从而扩展其结构多样性并改变其活性谱。此外，具有生物正交化学反应性的甲硫氨酸类似物（如叠氮基高丙氨酸和高丙炔基甘氨酸）的插入提供了与功能部分和荧光探针进行化学偶联以及乳链菌肽变体之间进行分子间偶联的机会。所有生成的乳链菌肽缀合物都保留了抗菌活性，这证实了该方法作为进一步研究其定位和作用模式的工具的潜力。
