Novel Amiloride Derivatives That Inhibit Bacterial Motility across Multiple Strains and Stator Types
Novel Amiloride Derivatives That Inhibit Bacterial Motility across Multiple Strains and Stator Types
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DOI：
10.1128/jb.00367-21
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发表时间：
2021-10-01
影响因子：
3.2
通讯作者：
Baker, M. A. B.
中科院分区：
文献类型：
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作者：
Islam, M. I.;Bae, J. H.;Baker, M. A. B.
细菌鞭毛运动 (BFM) 是一种蛋白质复合物，赋予细胞运动性并有助于生存和毒力。 BFM 由离子选择性膜蛋白复合物定子和直接连接到大灯丝（充当螺旋桨）的转子组成。定子复合体将穿过膜的离子耦合到驱动电机旋转的扭矩。驱动 BFM 旋转的最常见离子梯度是质子 (H+) 和钠离子 (Na+)。钠驱动的定子，如弧菌属 PomA/PomB 定子复合体中的定子，可以被钠通道抑制剂抑制，特别是 phenamil（一种有效且广泛使用的抑制剂）。然而，自从发现非那米尔以来，相对较少的新型钠动力抑制剂被描述。在这项研究中，我们从先前报道的阿米洛利衍生物的小型文库中鉴定了两种可能的运动抑制剂 HM2-16F 和 BB2-50F。我们使用了三种方法：对系留细胞旋转的影响、对自由游动细菌的影响以及对标记珠旋转的影响。我们发现，HM2-16F 和 BB2-50F 都可以停止由 Na+ 马达驱动的系留细胞的旋转，与匹配浓度下的 phenamil 相当，并且还可以停止由 H+ 马达驱动的系留细胞的旋转。在存在和不存在定子的情况下进行的珠子测量证实，与 phenamil 的既定作用模式相反，这些化合物不会通过与定子直接结合来抑制旋转。总体而言，HM2-16F 和 BB2-50F 在 Na+ 和 H- 定子类型以及致病性和非致病性菌株中都停止游动。 重要性 在这里，我们在寻找针对细菌运动的抗菌化合物的过程中表征了两种新型阿米洛利衍生物。这些化合物在 10 mM 浓度下可抑制多种菌株的鞭毛运动：从由质子或嵌合钠动力定子驱动鞭毛旋转的非致病性大肠杆菌，到质子动力致病性大肠杆菌（肠出血性大肠杆菌或尿路致病性大肠杆菌 [分别为 EHEC 或 UPEC]），最后是钠动力弧菌 溶藻菌。诸如此类的广泛抗运动化合物是我们在健康和农业环境中控制病原体毒力的重要工具。
The bacterial flagellar motor (BFM) is a protein complex that confers motility to cells and contributes to survival and virulence. The BFM consists of stators that are ion-selective membrane protein complexes and a rotor that directly connects to a large filament, acting as a propeller. The stator complexes couple ion transit across the membrane to torque that drives rotation of the motor. The most common ion gradients that drive BFM rotation are protons (H+) and sodium ions (Na+). The sodium-powered stators, like those in the PomA/PomB stator complex of Vibrio spp., can be inhibited by sodium channel inhibitors, in particular, by phenamil, a potent and widely used inhibitor. However, relatively few new sodium motility inhibitors have been described since the discovery of phenamil. In this study, we characterized two possible motility inhibitors, HM2-16F and BB2-50F, from a small library of previously reported amiloride derivatives. We used three approaches: effect on rotation of tethered cells, effect on free-swimming bacteria, and effect on rotation of marker beads. We showed that both HM2-16F and BB2-50F stopped rotation of tethered cells driven by Na+ motors comparable to phenamil at matching concentrations and could also stop rotation of tethered cells driven by H+ motors. Bead measurements in the presence and absence of stators confirmed that the compounds did not inhibit rotation via direct association with the stator, in contrast to the established mode of action of phenamil. Overall, HM2-16F and BB2-50F stopped swimming in both Na+ and H- stator types and in pathogenic and nonpathogenic strains.IMPORTANCE Here, we characterized two novel amiloride derivatives in the search for antimicrobial compounds that target bacterial motility. These compounds were shown to inhibit flagellar motility at 10 mM across multiple strains: from nonpathogenic Escherichia coli with flagellar rotation driven by proton or chimeric sodiumpowered stators, to proton-powered pathogenic E. coli (enterohemorrhagic E. coli or uropathogenic E. coli [EHEC or UPEC, respectively]), and finally, sodium-powered Vibrio alginolyticus. Broad antimotility compounds such as these are important tools in our efforts to control virulence of pathogens in health and agricultural settings.