Fujian-Taiwan Science and Technology Cooperation Base of Biomedical Materials and Tissue Engineering, Engineering Research Center of Industrial Biocatalysis, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, College of Chemistry and Materials Science, Fujian Normal University, Fuzhou, Fujian, China.
Biological Physics Group, Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK.
Bioorg Chem. 2023 Dec;141:106922. doi: 10.1016/j.bioorg.2023.106922. Epub 2023 Oct 17.
The broad-spectrum antimicrobial ability of de novo designed amphiphilic antimicrobial peptides (AMPs) G(IIKK)I-NH (G) and C-G(IIKK)I-NH (CG) have been demonstrated. Nonetheless, their potential as anti-quorum-sensing (anti-QS) agents, particularly against the opportunistic pathogen Pseudomonas aeruginosa at subinhibitory concentrations, has received limited attention. In this study, we proved that treating P. aeruginosa PAO1 with both AMPs at subinhibitory concentrations led to significant inhibition of QS-regulated virulence factors, including pyocyanin, elastase, proteases, and bacterial motility. Additionally, the AMPs exhibited remarkable capabilities in suppressing biofilm formation and their elimination rate of mature biofilm exceeded 95%. Moreover, both AMPs substantially downregulated the expression of QS-related genes. CD analysis revealed that both AMPs induced structural alterations in the important QS-related protein LasR in vitro. Molecular docking results indicated that both peptides bind to the hydrophobic groove of the LasR dimer. Notably, upon mutating key binding sites (D5, E11, and F87) to Ala, the binding efficiency of LasR to both peptides significantly decreased. We revealed the potential of antibacterial peptides G and CG at their sub-MIC concentrations as QS inhibitors against P. aeruginosa and elucidated their action mechanism. These findings contribute to our understanding of the therapeutic potential of these peptides in combating P. aeruginosa infections by targeting the QS system.
我们已经证明，在亚抑菌浓度下，新设计的两亲性抗菌肽（AMPs）G(IIKK)I-NH(G)和 C-G(IIKK)I-NH(CG)具有广谱抗菌能力。然而，它们作为抗群体感应（anti-QS）剂的潜力，特别是在亚抑菌浓度下针对机会性病原体铜绿假单胞菌，尚未得到充分关注。在这项研究中，我们证明了用这两种 AMP 在亚抑菌浓度下处理铜绿假单胞菌 PAO1 可以显著抑制 QS 调节的毒力因子，包括绿脓菌素、弹性蛋白酶、蛋白酶和细菌运动性。此外，AMP 还表现出显著抑制生物膜形成的能力，其成熟生物膜的消除率超过 95%。此外，这两种 AMP 都显著下调了与 QS 相关的基因表达。CD 分析表明，这两种 AMP 都能在体外诱导重要的 QS 相关蛋白 LasR 的结构改变。分子对接结果表明，这两种肽都结合到 LasR 二聚体的疏水性凹槽中。值得注意的是，当将关键结合位点（D5、E11 和 F87）突变为 Ala 时，LasR 与这两种肽的结合效率显著降低。我们揭示了抗菌肽 G 和 CG 在亚 MIC 浓度下作为铜绿假单胞菌 QS 抑制剂的潜力，并阐明了它们的作用机制。这些发现有助于我们了解这些肽通过靶向 QS 系统在治疗铜绿假单胞菌感染方面的治疗潜力。
