ABSTRACT
Recently, using structure-inspired drug design, we demonstrated that aminoalkyl derivatives of β-cyclodextrin inhibited anthrax lethal toxin action by blocking the transmembrane pore formed by the protective antigen (PA) subunit of the toxin. In the present study, we evaluate a series of new β-cyclodextrin derivatives with the goal of identifying potent inhibitors of anthrax toxins. Newly synthesized hepta-6-thioaminoalkyl and hepta-6-thioguanidinoalkyl derivatives of β-cyclodextrin with alkyl spacers of various lengths were tested for the ability to inhibit cytotoxicity of lethal toxin in cells as well as to block ion conductance through PA channels reconstituted in planar bilayer lipid membranes. Most of the tested derivatives were protective against anthrax lethal toxin action at low or submicromolar concentrations. They also blocked ion conductance through PA channels at concentrations as low as 0.1 nM. The activities of the derivatives in both cell protection and channel blocking were found to depend on the length and chemical nature of the substituent groups. One of the compounds was also shown to block the edema toxin activity. It is hoped that these results will help to identify a new class of drugs for anthrax treatment, i.e., drugs that block the pathway for toxin translocation into the cytosol, the PA channel.
摘要
最近,我们利用结构启发药物设计证明,β-环糊精的氨基烷基衍生物通过阻断炭疽毒素的保护性抗原(PA)亚基形成的跨膜孔来抑制炭疽致死毒素的作用。在本研究中,我们评估了一系列新的β-环糊精衍生物,目的是确定炭疽毒素的强效抑制剂。我们测试了新合成的具有不同长度烷基间隔的 β-环糊精庚-6-硫代氨基烷基和庚-6-硫代胍基烷基衍生物抑制细胞中致死毒素的细胞毒性以及阻断通过在平面双层脂膜中重建的 PA 通道的离子传导的能力。大多数受试衍生物在低浓度或亚摩尔浓度下对炭疽致死毒素的作用具有保护作用。它们还能在低至 0.1 nM 的浓度下阻断 PA 通道的离子传导。研究发现,这些衍生物在细胞保护和通道阻断方面的活性取决于取代基团的长度和化学性质。其中一种化合物还能阻断水肿毒素的活性。希望这些结果将有助于确定一类新的炭疽治疗药物,即阻断毒素转运到细胞膜的途径--PA 通道的药物。