Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, 9054 Dunedin, New Zealand.
Department of Biotechnology, Delft University of Technology, 2629 HZ Delft, The Netherlands.
Proc Natl Acad Sci U S A. 2018 Jul 10;115(28):7326-7331. doi: 10.1073/pnas.1803723115. Epub 2018 Jun 25.
Bedaquiline (BDQ), an inhibitor of the mycobacterial FF-ATP synthase, has revolutionized the antitubercular drug discovery program by defining energy metabolism as a potent new target space. Several studies have recently suggested that BDQ ultimately causes mycobacterial cell death through a phenomenon known as uncoupling. The biochemical basis underlying this, in BDQ, is unresolved and may represent a new pathway to the development of effective therapeutics. In this communication, we demonstrate that BDQ can inhibit ATP synthesis in by functioning as a H/K ionophore, causing transmembrane pH and potassium gradients to be equilibrated. Despite the apparent lack of a BDQ-binding site, incorporating the F subunit into liposomes enhanced the ionophoric activity of BDQ. We discuss the possibility that localization of BDQ at FF-ATP synthases enables BDQ to create an uncoupled microenvironment, by antiporting H/K Ionophoric properties may be desirable in high-affinity antimicrobials targeting integral membrane proteins.
贝达喹啉(BDQ)是一种分枝杆菌 FF-ATP 合酶抑制剂,它通过将能量代谢定义为一个强大的新靶标空间,彻底改变了抗结核药物的发现计划。最近有几项研究表明,BDQ 最终通过一种称为解偶联的现象导致分枝杆菌细胞死亡。BDQ 中这种现象的生化基础尚未解决,这可能代表着开发有效治疗方法的新途径。在本通讯中,我们证明 BDQ 可以通过充当 H/K 离子载体来抑制 的 ATP 合成,导致跨膜 pH 和钾梯度平衡。尽管明显缺乏 BDQ 结合位点,但将 F 亚基掺入脂质体中增强了 BDQ 的离子载体活性。我们讨论了这样一种可能性,即 BDQ 在 FF-ATP 合酶上的定位使 BDQ 能够在解偶联的微环境中发挥作用,通过反转运 H/K 离子载体特性可能是针对整合膜蛋白的高亲和力抗菌药物所需要的。