Quinoline-Based Inhibitors of Botulinum Neurotoxin A

基于喹啉的 A 型肉毒杆菌神经毒素抑制剂

• 批准号: 7383827
• 负责人: Norton P Peet
• 金额: $ 29.42万
• 依托单位: MICROBIOTIX, INC
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-03-15 至 2010-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7383827
• 关键词: Aerosols; Animal Experiments; Back; Bacteria; Binding; Biological; Biological Assay; Bioterrorism; Blood; Bontoxilysin; Botulinum Toxin Type A; Breathing; Cause of Death; Cell model; Cells; Chemicals; Cholinergic Agents; Clinical; Clostridial Neurotoxin; Clostridium; Clostridium botulinum; Clostridium butyricum; Clostridium tetani; Complex; Data Set; Development; Dose; Drug Design; Drug Kinetics; Endopeptidases; Enzyme Inhibitor Drugs; Enzyme Inhibitors; Enzymes; Ethylmaleimide; Exhibits; Exocytosis; Exposure to; Family; Goals; Human; In Vitro; Inhibitory Concentration 50; Interstitial Collagenase; Intravenous; Lead; Libraries; Life; Light; Liver Microsomes; Lung; Measures; Metabolism; Metalloproteases; Military Personnel; Modeling; Nerve Endings; Neurons; Neurotoxins; Numbers; Paralysed; Peripheral; Permeability; Pharmaceutical Preparations; Pharmacology; Phase; Phase III Clinical Trials; Poisoning; Population; Preparation; Process; Property; Protein Isoforms; Proteolysis; Reproduction spores; Safety; Screening procedure; Serotyping; Specificity; Stream; Structure; Structure-Activity Relationship; Synthesis Chemistry; Techniques; Therapeutic; TimeLine; Toxic effect; X-Ray Crystallography; Zinc; absorption; autonomic nerve; base; botulinum; cholinergic; design; drug development; drug discovery; improved; in vivo; inhibitor/antagonist; molecular modeling; neurotransmission; novel; pharmacophore; quinoline; receptor; scaffold; small molecule; tetanospasmin

DESCRIPTION (provided by applicant): The botulinum neurotoxins (BoNTs) represent a group of the most poisonous biological substances known (1- 3). Seven different serotypes of BoNTs (BoNT/A through BoNT/G) are secreted by the anaerobic spore- forming bacteria Clostridium botulinum, Clostridium butyricum and Clostridium baratii (4-7). Together with the tetanus neurotoxin (TeNT), which is produced by Clostridium tetani, the BoNTs comprise the clostridial neurotoxin (CNT) family (8). The lethal intravenous dose of BoNT serotype A (BoNT/A) in humans is 1-5ng/kg (9,10). If accidental exposure to BoNT occurs (e.g., from contaminated foodstuffs), loss of life or life-threatening paralysis can occur (11). Most importantly, the BoNTs have already been "weaponized" in a highly toxic aerosol form, and the BoNTs consequently pose a significant threat to both civilian and military populations (9, 12). Once inhaled into the lung, BoNTs are taken up by the blood stream, target the peripheral cholinergic nerve endings, and cause death by interrupting autonomic nerve function. The zinc-dependent endopeptidase light chain (LC) portion of BoNTs impair neuronal exocytosis through proteolysis of essential SNARE (soluble NSF-ethylmaleimide-sensitive factor attachment protein receptor) components of neurotransmission. The overall goal or this project is to develop small molecule inhibitors from multiple scaffolds of the BoNT/A light chain (LC) metalloprotease activity to treat botulinum poisoning. Small molecule quinoline-based inhibitors of BoNT /A LC have been identified by screening the NCI chemical diversity set (13, 14). These validated hit compounds are suitable starting points for BoNT/A inhibitor drug discovery by using structure-based drug design (SBDD) to improve and optimize their potencies and "drug-like" properties. In Phase I we will use proven techniques of medicinal and parallel synthetic chemistry, to produce "drug-like" molecules. We will use molecular modeling approaches and X-ray crystallography to explore the structural features of enzyme bound inhibitor complexes, and use parallel synthesis to prepare focused libraries of compounds related to idealized inhibitors. In an iterative process we will probe these focused compound libraries for structural features that contribute to tighter binding and more potent inhibition of the metalloprotase by measuring the enzymatic and cellular activities, and specificity of the enzyme inhibitors. We will use the growing data set to develop refined pharmacophore models that will guide the development of the structure activity relationships (SARs). Also, to accelerate the drug development process, and dramatically reduce the number of animal experiments needed in Phase II of this project, we will routinely assess all of our target compounds for optimal in vitro ADME-T (Absorption, Distribution, Metabolism, and Elimination and cyto- Toxicity) properties. We will produce an optimized lead compound and a back-up compound from a different scaffold. In Phase II, we will further optimize these leads for in vivo efficacy, pharmacokinetic properties, toxicity (in two species) and safety pharmacology to develop them as pre-IND clinical candidates (Phase III). "The botulinum neurotoxins are some of the most poisonous biological substances known. Loss of life or life-threatening paralysis can occur following exposure to these neurotoxins from contaminated foodstuffs or acts of bioterrorism. This proposal describes the preparation and development of novel drugs to treat botulinum poisoning."

描述（由申请人提供）：肉毒杆菌神经毒素（BoNT）代表一组已知毒性最强的生物物质（1- 3）。BoNT的七种不同血清型（BoNT/A至BoNT/G）由厌氧孢子形成细菌肉毒梭菌、丁酸梭菌和巴氏梭菌分泌（4-7）.与破伤风梭菌产生的破伤风神经毒素（TeNT）一起，BoNT构成梭菌神经毒素（CNT）家族（8）。A型肉毒杆菌毒素（BoNT/A）的静脉注射致死剂量为1- 5 ng/kg（9，10）。如果发生意外暴露于BoNT（例如，受污染的食物），可能会发生生命损失或危及生命的瘫痪（11）。最重要的是，BoNT已经以剧毒气溶胶的形式“武器化”，因此BoNT对平民和军人都构成了重大威胁（9，12）。一旦吸入肺中，BoNT被血流吸收，靶向外周胆碱能神经末梢，并通过中断自主神经功能导致死亡。BoNT的锌依赖性内肽酶轻链（LC）部分通过神经传递的必需SNARE（可溶性NSF-乙基马来酰亚胺敏感因子附着蛋白受体）组分的蛋白水解损害神经元胞吐作用。该项目的总体目标是从BoNT/A轻链（LC）金属蛋白酶活性的多个支架开发小分子抑制剂以治疗肉毒杆菌中毒。已通过筛选NCI化学多样性集（13，14）鉴定了BoNT /A LC的小分子喹啉抑制剂。这些经过验证的命中化合物是BoNT/A抑制剂药物发现的合适起点，通过使用基于结构的药物设计（SBDD）来改善和优化其效力和“药物样”性质。在第一阶段，我们将使用经过验证的药物和平行合成化学技术来生产“药物样”分子。我们将使用分子模拟方法和X射线晶体学来探索酶结合抑制剂复合物的结构特征，并使用平行合成来制备与理想化抑制剂相关的化合物的集中库。在一个迭代的过程中，我们将探测这些集中的化合物库的结构特征，有助于更紧密的结合和更有效的抑制金属蛋白酶通过测量酶和细胞的活性，和特异性的酶抑制剂。我们将使用不断增长的数据集来开发精细的药效团模型，以指导结构活性关系（SAR）的发展。此外，为了加速药物开发过程，并大幅减少本项目II期所需的动物实验数量，我们将定期评估所有目标化合物的最佳体外ADME-T（吸收、分布、代谢、消除和细胞毒性）特性。我们将从不同的支架中生产优化的先导化合物和备用化合物。在II期，我们将进一步优化这些先导化合物的体内疗效、药代动力学特性、毒性（在两个物种中）和安全药理学，以将其开发为IND前临床候选药物（III期）。“肉毒杆菌神经毒素是已知的最有毒的生物物质之一。在接触到这些来自受污染食品或生物恐怖主义行为的神经毒素后，可能会发生生命损失或危及生命的瘫痪。该提案描述了治疗肉毒杆菌中毒的新型药物的制备和开发。"