新型LasR群体感应抑制剂的设计、合成及抗铜绿假单胞菌活性研究

Biofilm associated drug-resistant infection caused by Pseudomonas aeruginosa (PA) has become a great threaten to the human health. There are no strategies that can effectively manage this infection in the clinical now. LasR, a key receptor protein of the Quorum Sensing (QS) in PA, regulates the biofilm formation via activating the overall QS system，inhibition of the LasR could help control the formation of biofilm..Computer-Aided Drug Design (CADD) has be used to screen 100,000 compounds of the IMB database (including about 500,000 compounds) based on the LasR protein, and 13 compounds has been obtained. The preliminary evaluation results showed that the expression of LasB up-regulated by LasR was inhibited obviously by 5 compounds. In this project, the further screen would be proceeded and compounds with structural diversity would be synthesized, SAR study and further modification would be followed up via the evaluation of inhibition activity. Finally, the pharmacodynamics of the hits along with their target validation would be investigated to explore novel quorum sensing inhibitors (QSI) which target the LasR protein and seek a breakthrough in solving the resistance of PA.

铜绿假单胞菌（Pseudomonas aeruginosa ，PA）生物被膜相关的耐药感染对人类健康构成严重的威胁，目前临床上尚无有效的治疗策略应对。LasR作为PA群体感应（QS）中的关键受体蛋白，正向调控整个QS系统，从而调控PA生物被膜的形成，靶向抑制LasR将有助于控制PA生物被膜的形成。.前期预实验利用计算机辅助药物设计对本所抗生素库约100,000 个化合物（共有500,000 个化合物）进行了基于LasR蛋白的虚拟筛选，得到的13个化合物经初步生物活性评价显示，5个化合物在20 μM浓度下对LasB（由LasR正向调控）的表达具有明显的抑制作用。本研究拟继续完成本所抗生素库的虚拟筛选，通过体外相关活性评价、构效关系研究、结构改造，药效学评价和靶点确证，探索全新骨架、靶点明确的小分子群体感应抑制剂（QSI），寻找解决PA耐药问题的突破口。

铜绿假单胞菌（Pseudomonas aeruginosa，PA）生物被膜相关的耐药感染对人类健康构成严重的威胁，目前临床上尚无有效的治疗策略应对。LasR作为PA群体感应（QS）上游调控系统中的关键受体蛋白，正向调控整个QS系统，从而调控PA生物被膜的形成。靶向抑制LasR不仅有助于控制PA生物被膜的形成，同时还抑制PA毒力因子的释放。通过对LasR蛋白晶体结构2UV0的深度解析，建立了基于受体蛋白的虚拟筛选模型并对本所抗生素库进行了虚拟筛选。同时，建立了基于荧光表达的报告菌株。通过化合物的合成、结构改造和报告菌株的活性评价，确定了3-硝基苯酚酯类化合物表现出优秀的LasR抑制活性。进一步，通过毒力因子绿脓菌素、生物膜、体内线虫实验，表明该化合物具有明显的抑制PA群体感应作用。最后，通过转录实验，证实该化合物抑制PA群体感应相关基因的表达。总之，本课题的研究成功筛选得到一类全新结构的群体感应小分子抑制剂。