Chemical probes to modulate acyl-homoserine lactone quorum signal synthesis

摘要 革兰氏阴性菌计数特异的N-酰基-L-高丝氨酸内酯群体感应信号 估计当地人口密度的环境，促进细胞间的交流和毒力。AHL 合成酶通过酶促偶联酰基-ACP/酰基-辅酶A和S-腺苷-L- 蛋氨酸代谢物，以促进细菌的群体感应。AHL的小分子抑制剂 合成酶将限制信号合成，干扰群体感应，从而带来巨大的希望 作为研究细菌中QS网络的化学工具。然而，设计AHL合成酶特异性抑制剂， 但这仍然是一个巨大的挑战。为了开发AHL合酶选择性抑制剂，我们最近开始了 一项评估AHL信号衍生物作为产物类似物抑制剂的概念验证研究 铜绿假单胞菌RhlI AHL合成酶。在这项研究中，我们证明了AHL类似物可以 作为化学探针，发现可以开发的新的抑制和激活结合口袋 强大的AHL合成酶特异性调节剂。在这项赠款申请中，我们将这种方法扩展到更广泛的 评估AHL类似化学探针在发现新的结合口袋中的效用的标尺，确定 AHL合酶调控的机制基础，以及制定AHL结合规则简而言之， 中链和长链偏爱AHL合酶。此外，我们将确定抑制和 激活口袋可用于开发AHL的新型底物和底物类似物抑制剂 合成酶。这些研究的成功完成将为抑制和激活的合理设计提供信息 袖珍定向AHL合成酶调节器。最后，本应用程序中描述的目标紧密结合在一起 区域计划的目标是：a)支持本科生的有价值的研究 重点机构，b)加强本国机构的研究环境，c)提供机会 让本科生参与生物医学研究。

Abstract Gram-negative bacteria count specific, N-acyl-L-homoserine lactone (AHL) quorum sensing (QS) signals in the environment to estimate local population densities, facilitate cell-cell communication and virulence. AHL synthases make AHL autoinducer signals by enzymatically coupling acyl-ACP/acyl-CoA and S-adenosyl-L- methionine metabolites to facilitate quorum sensing for the bacterium. Small molecule inhibitors of AHL synthase enzymes would limit signal synthesis, interrupt quorum sensing and thus hold significant promise as chemical tools to investigate QS networks in bacteria. Designing AHL synthase-specific inhibitors, however, does remain a significant challenge. To develop AHL synthase selective inhibitors, we recently embarked on a proof-of-concept study to evaluate the potential of AHL signal derivatives as product analog inhibitors of Pseudomonas aeruginosa RhlI AHL synthase. In this study, we demonstrated that AHL analogs could serve as ‘chemical probes’ to uncover novel inhibition and activation binding pockets that could be tapped to develop potent AHL synthase-specific modulators. In this grant application, we extend this approach on a broader scale to evaluate the utility of AHL analog chemical probes in discovering novel binding pockets, determining the mechanistic basis of AHL synthase modulation, and formulating the rules of AHL engagement in short, medium and long-chain preferring AHL synthases. Additionally, we will determine how the inhibition and activation pockets could be leveraged to develop novel substrates and substrate analog inhibitors of AHL synthases. Successful completion of these studies should inform the rational design of inhibition and activation pocket directed AHL synthase modulators. Finally, the goals described in this application are tightly aligned with the objectives of AREA program, which are to a) support meritorious research at an undergraduate focused institution, b) strengthen the research environment at the home institution and c) provide opportunity for undergraduate students to get involved in biomedical research.