Small Molecule Inhibitors of C. perfringens Epsilon-Toxin

描述(由申请人提供)：这项SBIR第一阶段提案的总体目标是使用创新生物公司开发的一种用于灭活造孔毒素的新方法来寻找抑制产气荚膜梭菌epsilon毒素作用的化合物。该方法基于与孔本身具有相同对称性的分子对目标孔的封闭。此前，我们在细胞实验和动物实验中证明，具有七重对称性的β-环糊精的全取代衍生物(β-CD)可以阻断炭疽杆菌保护性抗原(PA)形成的七聚体孔，并对炭疽毒素的致死作用具有保护作用。由于产气荚膜梭菌表观毒素形成一个类似于PA孔的七聚体跨膜孔，我们建议筛选我们的全取代β-CD衍生物文库以寻找表观毒素活性的抑制剂。本研究的第一阶段的具体目的是：(1)建立和验证β-CD衍生物对产气荚膜弧菌毒素形成的毛孔的阻断能力和抑制其细胞毒活性的能力。(2)从具有代表性的全取代β-CD衍生物文库中测试化合物的封闭和抑制活性，选择最有效的化合物作为抗毒素药物进行进一步开发。如果在这项可行性研究中找到了有效的表观毒素抑制剂，在第二阶段，我们将利用我们的初步测试数据和可用于产气荚膜弧菌表观毒素的晶体结构信息，结合计算化学来设计更多对表观毒素孔具有更强亲和力的β-CD衍生物。设计的化合物将被合成，并在体内和体外进行测试，最终目标是找到对抗产气荚膜梭菌epsilon毒素的新疗法。项目简介：由产气荚膜梭菌产生的Epsilon毒素是最致命的细菌毒素之一。它被视为一种潜在的生物武器，并被列入B类优先制剂清单。目前，尚无有效的治疗方法来治疗表观毒素介导的中毒，因此，迫切需要针对这种生物防御毒素的治疗方法的发展。

DESCRIPTION (provided by applicant): The overall goal of this SBIR Phase I proposal is to find compounds that inhibit C. perfringens epsilon-toxin action using a novel approach for the inactivation of pore-forming toxins developed at Innovative Biologics, Inc. It is based on the blocking of the target pore with molecules having the same symmetry as the pore itself. Previously, we demonstrated that per-substituted derivatives of beta-cyclodextrin (beta-CD) having a sevenfold symmetry could block the heptameric pore formed by Bacillus anthracis protective antigen (PA) and were protective against anthrax lethal toxin action in cell-based assays and in animals tests. Since C. perfringens epsilon -toxin forms a heptameric trans-membrane pore similar to the PA pore, we propose to screen our library of per-substituted beta-CD derivatives for inhibitors of epsilon - toxin's activity. The specific aims of this Phase I study are: (1) Establish and validate assays for testing the ability of beta -CD derivatives to block the pore formed by C. perfringens epsilon -toxin and to inhibit its cytotoxic activity. (2) Test blocking and inhibitory activity of compounds from a representative library of per-substituted beta -CD derivatives and select the most potent compounds for further development as anti-toxin drugs. Provided that effective inhibitors of epsilon -toxin are found in this feasibility study, in Phase II we will utilize our initial testing data and the crystal structure information available for C. perfringens epsilon -toxin in concert with computational chemistry to design additional beta-CD derivatives with enhanced affinity to the epsilon -toxin pore. The designed compounds will be synthesized and tested in vivo and in vitro with the eventual goal of finding new therapeutics against C. perfringens epsilon -toxin. Project Narrative: Epsilon toxin produced by Clostridium perfringens is one of the most lethal bacterial toxins. It is regarded as a potential biological weapon and is included in the list of category B priority agents. Currently, there is no effective treatment for the epsilon -toxin-mediated intoxication; therefore, a great need exists for the development of therapeutics against this biodefense toxin.