两株链霉菌中新颖安莎类抗生素的挖掘及其生物合成机制研究

The long-term, large-scale overuse and reliance of antibiotics in clinic led to serious antibiotic resistance in numerous bacteria. The discovery of novel antibiotics is of vital importance for human health. Ansamycins is a class of type I polyketide macrolide antibiotic with high medicinal potential, including rifamycin, geldanamycin, maytansine and many other well-kown drug precursors. Therefore, ansamycins owns predominant development potential. This project intends to focus on the excavation and biosynthesis of novel ansamycin antibiotics from microorganisms. On one hand, genome mining technology will be used to activate the pentaketide ansamycin biosynthesis gene cluster in Streptomyces sp. S035, then new skeleton pentaketide ansamycins will be tracked and separated. On the other hand, research on the biosynthesis mechanism of tetrapetalones and the accumulation of intermediates from the mutants will be carried out based on gene-cluster analysis. The biosynthetic mechanism of tetrapetalones will be elucidated at the first time, which could provide insights for the yield enhancement and structure optimization. This project integrates the traditional strategies of natural product research and the emerging genome mining technology through multidisciplinary intersection, directionally mining new skeleton ansamycins and providing lead compounds for novel pharmaceutical agent development.

临床上对抗生素的长期、大量的滥用与依赖导致多种细菌产生严重的耐药，新型抗生素的发掘对人类健康尤为重要。安莎是一类药用价值很高的Ⅰ型聚酮大环内酰胺类抗生素，其中包括利福霉素、格尔登霉素、美登木素等多个著名的药物先导，具有优越的开发潜力。本项目拟开展微生物中新颖安莎类抗生素的挖掘及其生物合成研究，一方面利用基因组挖掘技术激活链霉菌S035中的五酮安莎生物合成基因簇，追踪分离新骨架五酮安莎类化合物；另一方面根据基因簇分析开展对五酮安莎tetrapetalones生物合成机制研究以及突变株中间体的积累，首次阐明五酮安莎tetrapetalones的生物合成机制，为其产量优化和结构改造提供依据。本申请项目通过多学科交叉，整合天然产物研究传统方法与新兴基因组挖掘技术，定向挖掘新骨架安莎类化合物，为新药研发提供先导化合物。

临床上对抗生素的长期、大量的滥用与依赖导致多种细菌产生严重的耐药，新型抗生素的发掘对人类健康尤为重要。安莎是一类药用价值很高的大环内酰胺类抗生素，其中包括利福霉素、格尔登霉素、美登木素等多个著名的药物先导，具有优越的开发潜力。本项目通过调控基因组成型表达和启动子置换的方法激活链霉菌Streptomyce sp. S010中的tpt隐性安莎基因簇，分离得到7个新颖的五酮安莎类化合物，并通过体内敲除等策略对新颖五酮安莎类化合物的生物合成进行了研究；通过过表达构建S035的突变株，激活安莎基因簇，分离纯获得16个新化合物，包含6个新颖五酮安莎化合物，并初步的测定化合物的细胞毒活性，为后续对已有安莎化合物进行结构改造和优化奠定了基础。综上，本项目在生物信息学指导下，利用基因组挖掘技术成功激活隐性基因，策略性挖掘出新骨架安莎类化合物并解析其生物合成机制，也为新型抗生素的发现提供药物先导。