DEVELOPMENT OF MULTIVALENT ANTHRAX TOXIN INHIBITORS

描述（由申请人提供）：正如最近发生的事件所可怕地证明的那样，炭疽作为恐怖主义和战争的生物武器构成了致命的威胁。炭疽毒素的全身中毒几乎总是致命的，但没有有效的治疗方法。本申请的目标是开发有效的抑制剂，防止炭疽毒素复合物的组装。炭疽毒素是造成这种疾病的主要症状的原因。毒素由称为保护性抗原（PA）的宿主受体结合蛋白和称为致死因子（LF）和水肿因子（EF）的两种酶组成。这些蛋白质作为无毒单体从炭疽芽孢杆菌释放。它们扩散到宿主细胞表面并组装成两种类型的毒性蛋白复合物，即致死毒素（LF+PA）和水肿毒素（EF+PA）。 PA是将LF和EF从细胞表面转运到胞质溶胶的必要载体，在胞质溶胶中LF和EF发挥其细胞毒性作用。因此，抑制剂，防止结合LF或EF PA应提供一个有效的抗炭疽中毒治疗。 以前，我们已经确定了几个肽，结合PA弱，抑制LF或EF与PA的相互作用。我们假设，通过合作的相互作用，多价抑制剂（MVIs），其中多个拷贝的肽偶联到载体分子，将显示显着增强的抑制作用。在我们的初步研究中，我们已经合成了几种基于葡聚糖的MVI，其显示出比单独的肽更高的抑制活性。我们建议开发基于生物相容性，无毒，线性聚合物和环状低聚物作为载体的优化的MVI。 目标1. 优化以葡聚糖和果胶为载体的MVI。 目标2. 探索基于聚谷氨酸骨架的MVI。 目标3. 设计并开发了以β-环糊精为核心的七价冠醚型分子筛。 在目标1和2中，我们计划合成一系列肽-聚合物缀合物，其中肽-主链比和主链的分子大小系统地变化。在目标3中，我们将通过计算建模来辅助冠醚抑制剂的设计。我们将在我们建立的抑制试验中检测所有MVI，并在两种大鼠中毒模型中检测最活跃的MVI。这项研究开发的有效抑制剂可以帮助保护我们免受致命的炭疽病和炭疽生物恐怖主义的威胁。

DESCRIPTION (provided by applicant): As demonstrated so terribly by recent events, anthrax poses a deadly threat as a biological weapon of terrorism and warfare. Systemic intoxication by anthrax toxins is virtually always fatal but effective treatment is not available. The goal of this application is the development of potent inhibitors that prevent the assembly of anthrax toxin complexes. Anthrax toxins are responsible for the major symptoms of the disease. The toxins consist of a host receptor-binding protein termed protective antigen (PA) and two enzymes termed lethal factor (LF) and edema factor (EF). These proteins are released from Bacillus anthracis as nontoxic monomers. They diffuse to the surface of host cells and assemble into two types of toxic protein complexes, lethal toxin (LF+PA) and edema toxin (EF+PA). PA is the necessary vehicle that transports LF and EF from the cell surface to the cytosol where LF and EF exert their cytotoxic effects. Hence, inhibitors that prevent the binding of LF or EF to PA should provide an effective antitoxic therapy against anthrax. Previously, we have identified several peptides that bind PA weakly and inhibit the interactions of LF or EF with PA. We hypothesize that, through cooperative interactions, multivalent inhibitors (MVIs), in which multiple copies of a peptide are coupled to a carrier molecule, will display significantly enhanced inhibitory effects. In our preliminary study, we have synthesized several dextran-based MVIs that show higher inhibitory activities than peptides alone. We propose to develop optimized MVIs based on biocompatible, nontoxic, linear polymers and cyclic oligomers as carriers. Aim 1. To optimize MVIs based on dextran and pectin carriers. Aim 2. To explore MVIs based on polyglutamate backbones. Aim 3. To design and develop heptavalent "crown" MVIs based on (-cyclodextrin cores. In Aims 1 and 2, we plan to synthesize a series of peptide-polymer conjugates in which the peptide-to-backbone ratio and the molecular size of the backbone are systematically varied. In Aim 3, we will assist the design of crown inhibitors by computational modeling. We will test all MVIs in our established inhibition assays and the most active MVIs in two rat intoxication models. Potent inhibitors developed in this study can help to protect us from deadly anthrax disease and fight the threat of anthrax bioterrorism.