病原细菌多胺信号转导系统抑制剂的设计与合成

Evidence is emerging in recent years that the polyamine signal transduction system, which is the conserved transmembrane structure of microbial cells, plays a key role in the pathogenic process of bacterial pathogens. The system specifically recognizes the polyamine signals produced by host cells and pathogens and hence regulates the transcriptional expression of virulence genes and production of virulence factors. The polyamine signal transduction system thus represents a novel class of drug targets for developing a new generation of antibiotics. This project will focus on the complex crystal structures of the polyamine signal, which regulates the type III secretion system (T3SS) of Pseudomonas aeruginosa, and its receptor protein SpuE. The binding processes of various inhibitor candidates with the receptor under different environments will be simulated. Following molecular docking and molecular dynamics analysis, the binding mechanism of small molecules with receptor will be studied and a rational inhibitor-reception interaction model will be built up. Then virtual screening, rational design and synthesis of inhibitors based on the crystal structure of receptor protein SpuE will be carried out. Finally, the inhibitor candidates showing potent activity in suppression of T3SS and against P. aeruginosa infection will be identified following bioassay evaluation. The implementation of this project will provide theoretical and experimental basis for design of novel inhibitors against the polyamine signal transduction system, and may also present new ideas to solve the increasingly serious drug resistance problem of pathogenic bacteria. The research outcome will further enrich the strategies in design and developing novel antibiotics against bacterial signal transduction and regulatory systems, and contribute to the basic research and translational applications of infectious disease control in China.

位于病原细菌细胞周质的多胺信号转导系统在致病过程中起着非常关键的作用，此系统专一性识别寄主和病原产生的多胺信号从而调控致病基因的表达。因此，代表了一类研发新型农用及医用抗生素的全新靶标。本项目选择调控绿脓杆菌III型分泌系统表达的多胺信号与其受体蛋白SpuE的复合物晶体结构为研究对象，利用分子对接和分子动力学等方法模拟抑制剂与受体在不同环境下的结合过程，探讨小分子与受体的作用机理，建立合理的配体-受体模型，进行虚拟筛选和基于SpuE结构的抑制剂的合理设计与合成。最终通过生物活性评价，发现具有潜在应用前景的抑制绿脓杆菌入侵和感染的候选化合物。本项目的实施将为设计结构新颖的阻断病原多胺信号转导的特异性抑制剂提供实验和理论依据。为解决日趋严重的病原细菌抗药性问题提供新的思路。预期研究成果将进一步丰富基于细菌信号调控通讯系统创制新型抗生素的设计策略，为我国细菌病害防控的基础研究和转化应用做出贡献。

位于病原细菌细胞周质的多胺信号转导系统在致病过程中起着非常关键的作用，此系统专一性识别寄主和病原产生的多胺信号从而调控致病基因的表达。因此，代表了一类研发新型农用及医用抗生素的全新靶标。本项目选择调控绿脓杆菌III型分泌系统表达的多胺信号与其受体蛋白SpuE的复合物晶体结构为研究对象，利用分子对接和分子动力学等方法模拟抑制剂与受体在不同环境下的结合过程，探讨小分子与受体的作用机理，建立合理的配体-受体模型，进行虚拟筛选和基于SpuE结构的抑制剂的合理设计与合成。获得了一系列高效低毒的多胺衍生物。最终通过基因表达检测筛选抗致病物质，利用细胞毒性实验，果蝇感染模型以及动物肺炎模型实验进一步验证对绿脓杆菌毒性基因表达有抑制作用的活性化合物对其致病性的影响。发现具有潜在应用前景的抑制绿脓杆菌T3SS的新型抗感染类药物，并将这一关键思路与技术扩展应用到其他病原细菌的T3SS抑制剂开发上，在黄单胞菌T3SS抑制剂的创制方面也取得了一定的成果，构建了高效的GFP报告体系，筛选并设计得到一系列通过抑制T3SS进而阻断黄单胞菌致病性的具有潜在应用价值的抑制剂。本项目的实施为设计结构新颖的阻断病原多胺信号转导以及T3SS的特异性抑制剂提供实验和理论依据。为解决日趋严重的病原细菌抗药性问题提供新的思路。