The incorporation of noncanonical amino acids (ncAAs) with different side chains into a peptide is a promising technique for changing the functional properties of that peptide. Of particular interest is the incorporation of ncAAs into peptide-derived natural products to optimize their biophysical properties for medical and industrial applications. Here, we present the first instance of ncAA incorporation into the natural product cinnamycin in streptomycetes using the orthogonal pyrrolysyl-tRNA synthetase/tRNA^Pyl pair from Methanosarcina barkeri. This approach allows site-specific incorporation of ncAAs via the read-through of a stop codon by the suppressor tRNA^Pyl, which can carry different pyrrolysine analogues. Five new deoxycinnamycin derivatives were obtained with three distinct pyrrolysine analogues incorporated into diverse positions of the antibiotic. The combination of partial hydrolysis and MS/MS fragmentation analysis was used to verify the exact position of the incorporation events. The introduction of ncAAs into different positions of the peptide had opposite effects on the peptide’s biological activity.

中文翻译：

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链霉菌：非常规氨基酸掺入核糖体合成天然产物的新细胞工厂

将具有不同侧链的非规范氨基酸（ncAAs）掺入肽中是改变该肽功能特性的有前途的技术。特别令人感兴趣的是将ncAA掺入肽衍生的天然产物中，以优化其在医学和工业应用中的生物物理特性。在这里，我们介绍了使用正交^拟南芥-tRNA合成酶/ tRNA ^Pyl对从^草拟甲烷菌中将ncAA掺入链霉菌中的天然产物肉桂霉素中的第一个实例。这种方法允许NCAA锦标赛的位点特异性结合通过读通过抑制型tRNA终止密码子的^PYL，可以携带不同的吡咯赖氨酸类似物。通过将三种不同的吡咯赖氨酸类似物掺入到抗生素的不同位置中，获得了五种新的脱氧肉桂霉素衍生物。使用部分水解和MS / MS碎片分析相结合的方法来验证掺入事件的确切位置。将ncAA引入肽的不同位置对肽的生物活性具有相反的影响。