Quorum sensing (QS), a bacterial cell-to-cell communication system mediated by small molecules and peptides, has received significant interest as a potential target to block infection. The common pathogen Pseudomonas aeruginosa uses QS to regulate many of its virulence phenotypes at high cell densities, and the LasR QS receptor plays a critical role in this process. Small molecule tools that inhibit LasR activity would serve to illuminate its role in P. aeruginosa virulence, but we currently lack highly potent and selective LasR antagonists, despite considerable research in this area. V-06-018, an abiotic small molecule discovered in a high-throughput screen, represents one of the most potent known LasR antagonists but has seen little study since its initial report. Herein, we report a systematic study of the structure-activity relationships (SARs) that govern LasR antagonism by V-06-018. We synthesized a focused library of V-06-018 derivatives and evaluated the library for bioactivity using a variety of cell-based LasR reporter systems. The SAR trends revealed by these experiments allowed us to design probes with 10-fold greater potency than that of V-06-018 and 100-fold greater potency than other commonly used N-acyl-l-homoserine lactone (AHL)-based LasR antagonists, along with high selectivities for LasR. Biochemical experiments to probe the mechanism of antagonism by V-06-018 and its analogues support these compounds interacting with the native ligand-binding site in LasR and, at least in part, stabilizing an inactive form of the protein. The compounds described herein are the most potent and efficacious antagonists of LasR known and represent robust probes both for characterizing the mechanisms of LuxR-type QS and for chemical biology research in general in the growing QS field.

中文翻译：

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具有纳摩尔IC50值的铜绿假单胞菌群体感受器LasR的非天然拮抗剂的设计，合成和生化特性。

群体感应（QS）是一种由小分子和肽介导的细菌细胞间通讯系统，作为阻断感染的潜在靶标已引起了广泛的关注。常见的病原菌铜绿假单胞菌使用QS在高细胞密度下调节其许多毒力表型，而LasR QS受体在此过程中起关键作用。抑制LasR活性的小分子工具将有助于阐明其在铜绿假单胞菌毒力中的作用，但尽管在这一领域进行了大量研究，但我们目前仍缺乏高效和选择性的LasR拮抗剂。V-06-018是在高通量筛选中发现的一种非生物小分子，代表最有力的LasR拮抗剂之一，但自首次发表以来就很少进行研究。在这里 我们通过V-06-018报告了控制LasR拮抗作用的结构-活性关系（SAR）的系统研究。我们合成了V-06-018衍生物的聚焦库，并使用各种基于细胞的LasR报告系统评估了该库的生物活性。这些实验揭示的SAR趋势使我们能够设计出比V-06-018强10倍，比其他常用的基于N-酰基-1-高丝氨酸内酯（AHL）的LasR强100倍的探针拮抗剂，以及对LasR的高选择性。通过V-06-018及其类似物探索拮抗机制的生化实验支持这些化合物与LasR中的天然配体结合位点相互作用，并至少部分稳定了蛋白质的无活性形式。