Novel Therapeutics for Class B Protozoa

B 类原生动物的新疗法

基本信息

批准号：
7804552
负责人：
SHARON L REED
金额：
$ 138.06万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN DIEGO
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-05-15 至 2013-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7804552
关键词：
Active Sites Adverse effects Amebiasis Antiparasitic Agents Arginine Basic Science Biological Assay Canis familiaris Cathepsin E Cathepsins Cathepsins B Chagas Disease Charge Chemicals Chemistry Community Health Crystallization Crystallography Cyst Cysteine Cysteine Protease Cysteine Proteinase Inhibitors Data Development Disease Disease Outbreaks Drug Delivery Systems Drug Design Drug Kinetics Entamoeba histolytica Enzymes Epidemic Family Fibroblasts Food Foundations Future Giardia Giardia lamblia Giardiasis Goals Grant Homologous Gene Human Imidazole Immune In Vitro Infection Ingestion Inhibitory Concentration 50 International Intestines Laboratories Lead Libraries Ligands Mammalian Cell Modeling Molecular Target Mus Osteoporosis Papain Parasites Parasitic Diseases Pathogenesis Peptide Hydrolases Pharmaceutical Chemistry Pharmaceutical Preparations Pichia Play Positioning Attribute Primates Protozoa Recombinants Reporting Resistance Rodent Role SCID Mice Safety Screening procedure Series Specificity Structure Structure-Activity Relationship Subgroup Synthesis Chemistry Testing Toxic effect Toxicity Tests Toxicology Translating Water Work Xenograft procedure base cathepsin K chemotherapy design divinyl sulfone drug development drug discovery excystation foodborne foodborne outbreak global health high throughput screening human disease improved in vitro Model in vivo in vivo Model inhibitor/antagonist meetings monolayer mouse model novel novel therapeutics nutrition pre-clinical programs safety study scaffold small molecule structural genomics waterborne

项目摘要

DESCRIPTION (provided by applicant): Entamoeba histolytica and Giardia lamblia are Class B protozoa, which are major causes of water- and foodborne epidemics worldwide. Identification of new molecular targets for drug development is key for future therapy as resistance to the main class of drugs, imidazoles, has been detected in both parasites. This proposal brings together the expertise and interdisciplinary efforts of four major laboratories to build on basic research on parasite pathogenesis for a focus on drug development. We have shown that cysteine proteinases are critical for invasion of E. histolytica and excystation of G. lamblia. Cathepsins are an attractive drug target as they have been well characterized biochemically and structurally and are the focus of large inhibitor libraries. EhCP1, one of two cysteine proteinases unique to E. histolytica, is undergoing crystallization studies under Dr. Van Voorhis. The enzyme's unique requirement for arginine in the P2 position, led to the synthesis of a lead small molecule inhibitor by Dr. Roush's group with an IC50 for EhCP1 of <25 nM and >10-fold specificity for the amebic enzyme vs. human cathepsin B. We will test the proof of priniciple that we can develop an inhibitor that is sensitive, nontoxic, and specific for the protozoal cathepsins. Dr. Roush's group will synthesize additional compounds with improved potency and specificity for the parasitic enzymes based on SAR data we have generated. The lead compounds will then undergo basic toxicity testing and efficacy in standard models for in vitro and in vivo amebic infection. We will leverage the findings of the initial crystallization studies of EhCP1 to a structural based drug discovery to guide medicinal chemistry. The active, recombinant enzyme of the next drug target, GICP2, has been expressed by Dr. McKerrow's group and the effect of inhibitors on excystation will be validated with Dr. Gillin. We will also identify other potential classes of inhibitors by high throughput screening of Dr. McKerrow's focused 4000 compound library. These studies will provide the basis to identify novel cathepsin inhibitors against amebic and giardial cathepsins with the potential to target other protozoal enzymes in the future. Relevance. These studies will focus on new drug targets for amoebiasis and giardiasis, important causes of food- and waterborne outbreaks, and may lead to the development of a new class of antiparasitic drugs.

描述（由申请人提供）：溶组织内阿米巴和贾第鞭毛虫属于 B 类原生动物，是全世界水源性和食源性流行病的主要原因。确定药物开发的新分子靶点是未来治疗的关键，因为在这两种寄生虫中都检测到了对主要药物咪唑类药物的耐药性。该提案汇集了四个主要实验室的专业知识和跨学科努力，以寄生虫发病机制的基础研究为基础，重点关注药物开发。我们已经证明，半胱氨酸蛋白酶对于溶组织内阿米巴的入侵和兰伯利亚球菌的排泄至关重要。组织蛋白酶是一个有吸引力的药物靶点，因为它们在生化和结构上得到了很好的表征，并且是大型抑制剂库的焦点。 EhCP1 是溶组织内阿米巴特有的两种半胱氨酸蛋白酶之一，正在 Van Voorhis 博士的指导下进行结晶研究。该酶对 P2 位点精氨酸的独特需求，导致 Roush 博士的团队合成了一种领先的小分子抑制剂，其对 EhCP1 的 IC50 小于 25 nM，并且与人组织蛋白酶 B 相比，阿米巴酶的特异性高出 10 倍以上我们将测试原理证明，证明我们可以开发一种对原虫组织蛋白酶敏感、无毒且具有特异性的抑制剂。 Roush 博士的团队将根据我们生成的 SAR 数据合成其他化合物，以提高寄生酶的效力和特异性。然后，先导化合物将在体外和体内阿米巴感染的标准模型中进行基本毒性测试和功效测试。我们将利用 EhCP1 初步结晶研究的结果进行基于结构的药物发现，以指导药物化学。下一个药物靶标 GICP2 的活性重组酶已由 McKerrow 博士的小组表达，抑制剂对排泄的影响将由 Gillin 博士验证。我们还将通过高通量筛选 McKerrow 博士重点关注的 4000 种化合物库来鉴定其他潜在的抑制剂类别。这些研究将为鉴定针对阿米巴和贾第虫组织蛋白酶的新型组织蛋白酶抑制剂提供基础，并有可能在未来针对其他原虫酶。关联。这些研究将重点关注阿米巴病和贾第鞭毛虫病的新药物靶点，这是食物和水传播疾病爆发的重要原因，并可能导致新型抗寄生虫药物的开发。