Hit-to-lead optimization is a critical phase in drug discovery. Herein, we report on the fragment-based discovery and optimization of 2-aminopyridine derivatives as a novel lead-like structure for the treatment of the dangerous opportunistic pathogen Pseudomonas aeruginosa. We pursue an innovative treatment strategy by interfering with the Pseudomonas quinolone signal (PQS) quorum sensing (QS) system leading to an abolishment of bacterial pathogenicity. Our compounds act on the PQS receptor (PqsR), a key transcription factor controlling the expression of various pathogenicity determinants. In this target-driven approach, we made use of biophysical screening via surface plasmon resonance (SPR) followed by isothermal titration calorimetry (ITC)-enabled enthalpic efficiency (EE) evaluation. Hit optimization then involved growth vector identification and exploitation. Astonishingly, the latter was successfully achieved by introducing flexible linkers rather than rigid motifs leading to a boost in activity on the target receptor and anti-virulence potency.

中文翻译：

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灵活的片段生长增强了针对铜绿假单胞菌毒力的群体感应抑制剂的效价。

领先的优化是药物发现中的关键阶段。在这里，我们报告基于片段的发现和优化的2-氨基吡啶衍生物作为一种新型的铅样结构，用于治疗危险的机会性病原体铜绿假单胞菌。我们通过干扰假单胞菌喹诺酮信号（PQS）群体感应（QS）系统来追求创新的治疗策略，从而消除细菌致病性。我们的化合物作用于PQS受体（PqsR），PQSR是控制各种致病性决定因素表达的关键转录因子。在这种目标驱动的方法中，我们利用了通过表面等离振子共振（SPR）进行的生物物理筛选，然后进行了等温滴定量热（ITC）的焓效率（EE）评估。命中优化然后涉及生长载体的鉴定和开发。令人惊讶的是，后者通过引入柔性接头而不是刚性基序而成功实现，从而导致对靶受体的活性和抗毒力增强。