Novel Therapeutic Approaches to Pathogen Inactivation

描述（由申请人提供）：炭疽芽孢杆菌和其它细菌病原体是生物恐怖主义和生物战竞技场中更显著的威胁之一，而其它革兰氏阳性病原体（包括金黄色葡萄球菌和A组链球菌菌株）的耐药菌株的出现也导致了对治疗攻击的新途径的迫切需要.该提案旨在探索靶向IscU的可行性，IscU是细胞铁代谢和活力的必需蛋白质，作为对抗细菌病原体的治疗方法。该提案还建立在一个新的治疗平台上，该平台是该实验室正在进行的研究的重点-即催化药物分子的设计，该分子不可逆地使治疗靶点的多个拷贝结合。实验目标是通过设计和评价先导药物候选物来证明ISCU-分子伴侣复合物作为治疗靶点的可行性，并在细胞测定中对其有效性进行客观测量。拟议的研究将测试的假设，即细菌伴侣DnaK与集群组装蛋白IscU的相互作用可以通过使用的肽设计，是基于伴侣DnaK的IscU识别基序抑制。该假设将基于IscU簇组装和转移反应的功能测定以及DnaK-IscU和DnaK-肽结合的量热研究进行评估。预计的结果包括鉴定抑制肽，其阻断铁硫簇生物合成中必需蛋白质IscU的功能。这些肽将是药物开发的主要候选者。将进行对照实验以评价对等效人IscU和伴侣蛋白的响应。候选金属肽可以有效地以催化多周转方式抑制ISCU-伴侣蛋白复合物的假设也将通过类似的策略进行测试。将在设计用于证明细胞摄取和活性的细胞测定中验证治疗候选物。将进行对照实验，以验证不存在针对人细胞系的毒性反应。公共卫生相关性：药物发现仍然是医学科学的首要任务。耐药性现象已经提高了对新的药物类别以及新的作用模式的需求。近年来，我们一直致力于开发一种独特的药物设计方法，包括识别和随后的治疗靶点的不可逆失活。这一概念允许改进的目标选择性和较低的剂量要求，并将针对与生物恐怖主义和生物战相关的治疗目标进一步开发，同时还解决了由其他革兰氏阳性病原体（包括金黄色葡萄球菌和A组链球菌菌株）的耐药菌株的出现引起的问题。

DESCRIPTION (provided by applicant): Bacillus anthracis and other bacterial pathogens are among the more pronounced threats in the arena of bio- terrorism and biological warfare, while the occurrence of resistant strains of other gram positive pathogens (including Staphylococcus aureus, and group A Streptococcus strains) has also resulted in an urgent need for new avenues of therapeutic attack. This proposal seeks to explore the feasibility of targeting IscU, an essential protein for cellular iron metabolism and viability, as a therapeutic approach against bacterial pathogens. The proposal also builds on a novel therapeutic platform that is a focus of on-going research in this laboratory - namely, the design of catalytic drug molecules that irreversibly inactivate multiple copies of therapeutic targets. The experimental goals are to demonstrate the viability of IscU-chaperone complexes as therapeutic targets through the design and evaluation of lead drug candidates, and perform objective measures of their effectiveness in cellular assays. The proposed research will test the hypothesis that the interaction of the bacterial chaperone DnaK with the cluster assembly protein IscU can be inhibited by use of a peptide design that is based on the IscU recognition motif for chaperone DnaK. This hypothesis will be evaluated on the basis of functional assays of IscU cluster assembly and transfer reactions, and calorimetric investigations of DnaK- IscU and DnaK-peptide binding. The projected outcomes include identification of inhibitor peptides that block the function of the essential protein IscU in iron-sulfur cluster biosynthesis. Such peptides will be lead candidates for drug development. Control experiments will be carried out to evaluate the response against the equivalent human IscU and chaperone proteins. The hypothesis that candidate metallopeptides can effectively inactivate the IscU-chaperone complex in a catalytic multiturnover manner will also be tested by a similar strategy. Therapeutic candidates will be validated in cellular assays designed to demonstrate both cellular uptake and activity. Control experiments will be carried out to verify the absence of a toxic response against human cell lines. PUBLIC HEALTH RELEVANCE: Drug discovery remains a top priority in medical science. The phenomenon of drug resistance has heightened the need for both new classes of pharmaceutical as well as novel modes of action. In recent years we have worked to develop a distinct approach to drug design that involves both recognition and subsequent irreversible inactivation of therapeutic targets. This concept allows for improved target selectivity and lower dosage requirements and will be further developed against therapeutic targets of relevance to bio-terrorism and biological warfare, while addressing also problems arising from the occurrence of resistant strains of other gram positive pathogens (including Staphylococcus aureus, and group A Streptococcus strains).