DRUGS DIRECTED AGAINST ISOPRENOID BIOSYNTHESIS

多药结核病在全世界的流行率正在增加，这使得寻找新的抗结核药物势在必行。对M.结核病将大大促进这一进程。 该提案的总体目标是确定与M细胞壁合成相关的药物靶点。结核病，表征酶参与，并确定药物开发的先导化合物。这个项目（3）集中在类异戊二烯生物合成中所涉及的酶的作用。类异戊二烯生物合成可以被认为是细胞壁合成的最早步骤之一，使其成为理想的潜在药物靶标。类异戊二烯化合物，如聚异戊二烯磷酸盐，甲基萘醌和可能的hopanoids在分枝杆菌代谢中起着至关重要的作用，在某些情况下是必不可少的。观察到M.结核杆菌对抑制类异戊二烯生物合成的局部抗生素杆菌肽敏感，这表明类异戊二烯化合物的合成是结核杆菌存活所必需的。结核许多细菌类异戊二烯在结构上与真核生物中发现的不同，但对这些化合物在M.结核最初的假设是 原核生物使用与真核生物相同的生物合成途径来合成类异戊二烯。我们相信，识别和表征参与独特和必要的生物合成途径的酶将导致开发用于治疗结核病的新药。考虑到这一点，我们已经开发了以下项目，其中我们将尝试：1）使用中等至高通量测定法鉴定抑制1-脱氧木酮糖-5-磷酸合酶（DXS）的化合物，DXS是一种在哺乳动物中未发现的细菌类异戊二烯生物合成所必需的酶。2)描述分枝杆菌特有的类异戊二烯生物合成途径。

The prevalence of multi-drug tuberculosis is increasing worldwide making the search for new anti-tuberculosis drugs imperative. A greater understanding of the basic biochemistry of M. tuberculosis will greatly facilitate this process. The overall objective of this proposal is to identify drug targets relating to cell wall synthesis in M. tuberculosis, characterize the enzymes involved and identify lead compounds for drug development. This project (3) focuses on the role played by the enzymes involved in isoprenoid biosynthesis. Isoprenoid biosynthesis can be considered one of the earliest steps in cell wall synthesis making it an ideal potential drug target. Isoprenoid compounds such as polyprenyl phosphate, menaquinone and possibly hopanoids play crucial and in some cases essential roles in mycobacterial metabolism. The observation that M. tuberculosis is susceptible to the topical antibiotic bacitracin, which inhibits isoprenoid biosynthesis demonstrates that the synthesis of the isoprenoid compounds is required for the survival of M. tuberculosis. Many bacterial isoprenoids are structurally distinct from those found in eukaryotes yet little is known about the biosynthesis of these compounds in M. tuberculosis. It was originally assumed that prokaryotes use the same biosynthetic pathways as eukaryotes for the synthesis of isoprenoids This assumption has recently been shown to be correct. We believe that identification and characterization of enzymes involved in unique and essential biosynthetic pathways will lead to the development of novel drugs for the treatment of tuberculosis. With that in mind, we have developed the following project in which we will attempt to: 1) identify compounds that inhibit 1-deoxyxylulose-5-phosphate synthase (DXS), an enzyme essential for bacterial isoprenoid biosynthesis that is not found in mammals, using a medium to high throughput assay. 2) Characterize the portions of the isoprenoid biosynthetic pathway that are unique to mycobacteria.