Purine Analog Anti-Mycobacterial Drug Development

描述(由申请人提供)： 通过NIAID赞助的结核病抗微生物获取和协调机制(TAACF)，我们已经鉴定了许多抗结核分枝杆菌先导化合物，它们在结构上与嘌呤碱基和核苷相似。在目前的赠款期间(1999至2003年)，我们(1)合成了许多新化合物，并评估了它们对结核分枝杆菌的活性，(2)表征了其中一种先导化合物(2-甲基腺苷)的生化药理，以及(3)开始表征参与挽救结核分枝杆菌嘌呤的酶。在新的拨款方案中，我们计划继续这些研究，以进一步了解结核分枝杆菌嘌呤挽救途径中涉及的酶，并设计和合成具有选择性抗结核分枝杆菌活性的新制剂。由于开发核苷类似物用于治疗癌症和病毒性疾病，人们对参与嘌呤回收的人类酶的底物需求知道得很多。然而，目前对结核分枝杆菌中这些酶的底物特性知之甚少。我们已经确定了3种在结核分枝杆菌中表达的嘌呤挽救酶，它们可以用于开发新的选择性抗/W.TB药物。其中两种酶(腺苷裂解和鸟苷激酶)在人类细胞中不表达，我们最近发现第三种酶(腺苷激酶)具有独特的特性，也可以用于核苷类似物的选择性激活。这些酶的生化和遗传特征应该提供有价值的信息，这些信息将有助于基于人类和结核分枝杆菌嘌呤代谢的代谢差异合理设计和开发新的药物。 建议的具体目标是：(1)鉴定、克隆、表达和纯化结核分枝杆菌腺苷裂解和鸟苷激酶活性；(2)结核分枝杆菌腺苷激酶、腺苷裂解和鸟苷激酶活性的生化特征；(3)具有有效和选择性抗结核分枝杆菌活性的新制剂的代谢研究。结核分枝杆菌活性；以及(4)设计和合成对结核分枝杆菌具有选择性活性的嘌呤和嘌呤核苷类似物。

DESCRIPTION (provided by applicant): Through the NIAID-sponsored Tuberculosis Anti-microbial Acquisition and Coordinating Facility (TAACF), we have identified numerous anti-Mycobacterium tuberculosis lead compounds, which are structurally similar to purine bases and nucleosides. In the current grant period (1999 to 2003) we have (1) synthesized many new compounds and evaluated them for activity against M. tb, (2) characterized the biochemical pharmacology of one of the lead compounds (2-methyladenosine), and (3) begun the characterization of the enzymes involved in purine salvage in M. tb. In the new grant proposal we plan to continue these studies to further our understanding of the enzymes involved in the purine salvage pathway in M. tb and to design and synthesize new agents with selective activity against M. tb. Much is known about the substrate requirements of human enzymes involved in purine salvage, because of the considerable effort to develop nucleoside analogs for the treatment of cancer and viral diseases. However, very little is currently known about the substrate characteristics of these enzymes in M. tb. We have identified 3 purine salvage enzymes that are expressed in M. tb that could be exploited in the development of new selective anti-/W. tb agents. Two of these enzymes (adenosine cleavage and guanosine kinase) are not expressed in human cells and we have recently shown that the third enzyme (adenosine kinase) has unique characteristics that could also be used for selective activation of nucleoside analogs. The biochemical and genetic characterization of these enzymes should provide valuable information that will be useful in the rational design and development of new agents based on metabolic differences in purine metabolism between humans and M. tb. The proposed specific aims to accomplish the goals of this grant proposal are: (1) identification, cloning, expression, and purification of M. tb adenosine cleavage and guanosine kinase activities; (2) biochemical characterization of M. tb adenosine kinase, adenosine cleavage, and guanosine kinase activities; (3) metabolic studies with new agents that have potent and selective anti-M. tb activity; and (4) design and synthesis of purine and purine nucleoside analogs with selective activity against M. tb.