Targeting Non-mammalian Isoprenoid Biosynthesis

 描述(申请人提供)：传染病中抗菌素耐药性的增加对人类健康构成严重威胁，要求开发新的抗菌药疗法。甲基赤藓糖醇磷酸(MEP)合成异戊二烯的途径是不可缺少的，它由多种病原体中的七个酶靶点组成，其中超过一半的细菌病原体被疾控中心列为对公众健康的严重或紧急威胁。尽管如此，只有IspC抑制剂磷霉素通过了临床评估，突显了针对这一途径的临床有用药物的缺乏。我们的研究寻求新的方法来阻止人类病原体中必要的异戊二烯类物质的产生。建议的研究将集中在MEP途径中不发达的靶点，包括依赖于硫胺素二磷酸的1-脱氧-D-木酮糖-5-磷酸(DXP)合成酶催化的第一步，以及由环二磷酸合成酶ISPF催化的第五步。第三个研究领域将侧重于通过早期阶段的类异戊二烯生物合成来定位通量。我们将采取多学科的方法来：1)描述DXP合成酶催化和构象动力学的独特方面，可用于选择性抑制剂设计；2)研究ISPF作为潜在的新抗菌靶点生产MEcDP的前馈调节机制；3)利用简单的底物类似物，开发通过MEP途径的早期步骤抑制通量的策略。我们的研究有望建立我们对独特的酶行为的知识，这些行为代表了药物干预的潜在要点，这可能导致新的抗菌疗法的开发。

 DESCRIPTION (provided by applicant): The increasing occurrence of antimicrobial-resistance in infectious diseases poses a serious threat to human health, and demands the development of new antimicrobial therapies. The indispensable methylerythritol phosphate (MEP) pathway to isoprenoids comprises seven enzymatic targets in a wide variety of pathogens, including greater than half of bacterial pathogens prioritized by the CDC as serious or urgent threats to public health. Despite this, only the IspC inhibitor fosmidomycin has advanced through clinical evaluation, highlighting the lack of clinically useful agents targeting this pathway. Our research seeks new approaches to block essential isoprenoid production in human pathogens. The proposed studies will focus on under-developed targets in the MEP pathway, including the first step catalyzed by thiamin diphosphate-dependent 1-deoxy-D-xylulose 5-phosphate (DXP) synthase, and the fifth step catalyzed by cyclodiphosphate synthase IspF. A third area of research will focus on targeting flux through early stage isoprenoid biosynthesis. We will take multidisciplinary approaches to: 1) delineate the unique aspects of DXP synthase catalysis and conformational dynamics that can be exploited for selective inhibitor design, 2) examine a putative feed-forward regulatory mechanism for MEcDP production by IspF as a potential new antimicrobial target, and 3) develop strategies to inhibit flux through the early steps of the MEP pathway using simple substrate analogs. Our research is expected to build our knowledge of the unique enzyme behaviors that represent potential points for pharmacologic intervention, which could lead to the development of new antimicrobial therapies.