计算机辅助药物设计筛选嗜水气单胞菌AhyⅠ合成酶抑制剂

Computer-aided drug design for discovery of small-molecule inhibitors of N-acyl-homoserine lactone synthase in Aromonas hydrophila

【背景】AhyⅠ合成酶在嗜水气单胞菌(Aromonas hydrophila)群体感应调控毒力产生中发挥着关键作用。【目的】研究其结构以寻找高效抑制剂,切断细菌致病性的源头,具有极其重要的意义。【方法】利用已解析的蛋白质结构为模板,运用同源模建和分子动力学模拟手段,成功建立了AhyⅠ合成酶的三维结构。接下来,基于先前研究的基础,选取2个高效抑制剂N-3-氧代己酰基高丝氨酸内酯(N-3-oxo-hexanoyl-homoserine lactone,NOO)和5-脱氧-5-甲硫腺苷(5'-deoxy-5'-methylthioadenosine,MTA)以及传统中药中的部分活性成分,共选取214个候选配体与受体蛋白进行分子对接。【结果】筛选出4个潜在抑制剂,经过最小抑菌浓度(minimal inhibit concentration, MIC)值、生长曲线、紫色菌素、生物膜形成、胞外蛋白酶、群集运动和泳动实验验证后,发现青蒿素可以作为嗜水气单胞菌群体感应系统的高效抑制剂。【结论】传统中药青蒿素为水产养殖业中嗜水气单胞菌的有效防治提供基础,在治疗细菌感染方面具有广阔的应用前景。

[Background]The N-acyl-homoserine lactone synthase AhyⅠplays a critical role in regulating the production of virulence in Aeromonas hydrophila biofilm.[Objective]To reveal the structure of AhyⅠ,so as to discover effective inhibitors that can disrupt bacterial pathogenicity at the source.[Methods]We constructed the three-dimensional structure of AhyⅠby employing homology modeling and molecular dynamics simulation with a resolved protein structure as a template.On the basis of previous research results,we selected 214 candidate ligands including two highly effective inhibitors(NOO and MTA)and active components from Chinese herbal medicines to undergo molecular docking with the receptor protein.[Results]Through this process,we identified four potential inhibitors.The minimum inhibitory concentration(MIC),bacterial growth curve,violacein production,biofilm formation,extracellular protease activity,and bacterial swarming and swimming performance showed that artemisinin served as a highly efficient inhibitor of A.hydrophila quorum sensing.[Conclusion]Artemisinin from the Chinese herbal medicine serves the prevention and treatment of infections of waterborne bacteria in the aquaculture industry,holding a promising prospect for the treatment of bacterial infections in the future.