Design and Study of IspF Inhibitors as Antibacterial Agents

描述(由申请人提供)：迫切需要发现新的抗感染药物来治疗细菌感染。甲基赤藓糖醇磷酸(MEP)途径对大多数形式的细菌的生存是必不可少的。MEP途径由七种酶组成。该途径中的第五个酶是甲基赤藓糖醇环二磷酸合成酶(ISPF)，该酶的活性部位在不同种类的革兰氏阴性菌中高度相似。抑制ISPF酶的类药物小分子可能会导致一类新的抗生素。细菌ISPF酶的有效抑制剂尚未确定。人类中不存在MEP途径，这为开发新的酶抑制剂提供了机会，从而导致抗菌剂对人类的毒性降低。我们的长期目标是合成有效的MEP途径酶抑制剂，以验证该途径中的哪些酶将作为小分子抗菌剂的靶标最有效。本申请的目的是寻找MEP途径ISPF酶的有效小分子抑制剂，它们是有效的、类药物的先导分子，以便作为工具化合物使用。在这项建议中，我们将通过片段筛选发现的HIT分子推进到先导化合物中，作为工具来验证MEP途径抑制作为新型抗菌剂的作用机制。为了实现这一目标，我们将利用结构生物学和现代药物化学的原理来设计和合成新的化合物。我们将针对ISPF酶对这些化合物进行测试，以评估它们的效力，并指导新的甚至更有效的化合物的合成。新合成的化合物将被测试其抗菌效果。显示出抗生素功效的化合物将被进一步鉴定，以确定它们实际上是通过监测ISPF酶的产物来抑制细胞中的ISPF酶的。此外，还将监测MEP途径的下游产物、维生素K2和辅酶Q，以确认其作用机制，并验证抑制ISPF酶是一种可能导致一类新抗生素的方法。这项研究是跨学科性质的，将包括北大的研究生和本科生，并加强他们的教育经验，以及加强在北大的研究经验。

DESCRIPTION (provided by applicant): There is a critical need to discover new anti-infective agents to treat bacterial infections. The methylerythritol phosphate (MEP) pathway is essential to the survival of most forms of bacteria. The MEP pathway consists of seven enzymes. The fifth enzyme in the pathway is IspF (methylerythritol cyclodiphosphate synthase) and the active site for this enzyme is highly similar among different species of Gram negative bacteria. Small drug-like molecules that inhibit the IspF enzyme may lead to a new class of antibiotics. Potent inhibitors have yet to be identified for the bacterial IspF enzyme. The MEP pathway is absent in humans, which provides an opportunity for novel enzyme inhibitor development leading to antibacterial agents with reduced potential for toxicity in humans. Our long-term goal is to synthesize potent inhibitors of MEP pathway enzymes to validate which enzymes in the pathway will be most effective as targets for small molecule antimicrobial agents. The objective of this application is to identify potent small molecule inhibitors of the MEP pathway IspF enzyme, which are potent and drug-like leads so that they can be used as tool compounds, In this proposal, we will advance hit molecules that were discovered by fragment screening into lead compounds that can be used as tools to validate MEP pathway inhibition as a mechanism for new antibacterial agents. To accomplish this goal we will use structural biology and principles of modern medicinal chemistry to design and synthesize new compounds. We will assay the compounds against the IspF enzyme to assess their potency and guide the synthesis of new and even more potent compounds. The newly synthesized compounds will be assayed for their antibacterial efficacy. Compounds that display antibiotic efficacy will be further assaye to determine that they are actually inhibiting the IspF enzyme in cells by monitoring the product of the IspF enzyme. In addition the downstream products of the MEP pathway, vitamin K2 and coenzyme Q will be monitored to confirm the mechanism of action and validate that inhibition of the IspF enzyme is a could lead to a new class of antibiotics. This research is interdisciplinary i nature and will involve both graduate and undergraduate students at NIU and strengthen their educational experience as well as enhance the research experience at NIU.