Targeting MraY: Synthesis and Validation of MraY Inhibitors

描述(由申请人提供)：一种来自自然来源的mray抑制剂，卡普拉霉素，在结核分枝杆菌小鼠感染模型中显示出显著的活性。Muraymycins具有卡普拉霉素的共同核心结构，但它们的结构多样性存在于一个无环的复杂脱脂肽部分和C5‘-糖附加部分中。惠氏研究小组强调了Muraymycin A1对金黄色葡萄球菌有希望的体内抗菌活性。因此，验证Muraymycin A1在体外和体内对结核分枝杆菌的疗效是我们感兴趣的。而真菌菌株(Streptomyces spp.用于生产Muraymycin A1和任何同系物的Muraymycin A1和任何同系物都不可用，并且Muraymycin A1必须合成以用于体外化合物图谱。因此，我们将建立完整的Muraymycin A1的合成路线，以获得足够的分子(特定目标1)。此外，1)这些结构的复杂性，2)选择性地对所需位置进行化学修饰，以及3)不方便地检测Mtb mray酶，包括难以获得足够的mray底物Park‘s核苷酸，从而阻碍了Muraymycin A1和Capuramcin的药物化学程序，包括药代动力学方面的改进。我们完成了一种可扩展的化学酶法全合成Park‘s核苷酸及其荧光探针，并建立了一种使用包括mray、Murg和十一烯基磷酸在内的细胞膜富集组分的简便的mray抑制物检测方法。此外，在过去的几年里，我们对尿苷-氨基醇分子在溶液中或在聚合物载体上的合成可及性获得了广泛的知识。我们将继续设计和合成新的尿苷-氨基-醇衍生物，以鉴定Muraymycins和Capuramcin的最小和基本结构(特定目标2)。将在CSU分枝杆菌研究实验室(特定目标3)对产生的分子进行体外分析，以对抗结核分枝杆菌和对药物敏感和耐药的结核分枝杆菌。 公共卫生相关性：耐多药结核分枝杆菌(MDR-TB)已在医院和教养机构中发生，并经常发生在艾滋病毒感染患者中。耐多药结核病患者对现有药物的临床反应很差，在某些情况下根本没有反应。这项赠款申请的长期目标是为耐多药结核病开发新的药物先导。

DESCRIPTION (provided by applicant): A MraY inhibitor from a natural source, capuramycin, exhibited significant activity in vivo using M. tuberculosis mouse infection model. Muraymycins possess a common core structure of capuramycin, however, their structural diversity is observed in an acyclic complex depsipeptide moiety and the C5'-sugar-appended. Promising in vivo antibactericidal activity of muraymycin A1 against S. aureus was highlighted by the Wyeth-Research groups. Thus, it is of our interest to validate the efficacy of muraymycin A1 in vitro and in vivo against M. tuberculosis. However, the fungus strain (Streptomyces spp. LL-AA896) used to produce muraymycin A1 and any congeners are not available, and muraymycin A1 has to be synthesized for the in vitro compound profiling. Thus, we will establish the synthetic route for intact muraymycin A1 to obtain enough molecules (Specific Aim 1). Furthermore, medicinal chemistry programs of muraymycin A1 and capuramycin with an aim to improve the efficacy including pharmacokinetics are hampered by 1) the complexity of these structures, 2) difficulty in chemically modifying the desired positions selectively, and 3) no convenient assay against Mtb MraY enzyme including difficulty in obtaining enough MraY substrate, Park's nucleotide. We accomplished a scalable chemoenzymatic and total synthesis of Park's nucleotide and its fluorescent probe, and established a convenient MraY inhibitor assay using a cell envelop enriched fraction including MraY, MurG and decaprenylphosphate. In addition, over the past years we obtained extensive knowledge of synthetic accessibility of uridine-amino-alcohol containing molecules in solution or on the polymer- support. We will continue designing and synthesizing new uridine-amino-alcohol derivatives in order to identify the minimal and essential structures of muraymycins and capuramycin (Specific Aim 2). In vitro profiling of the generated molecules against Mtb MraY and drug-sensitive and -resistant M. tuberculosis will be performed at the CSU Mycobacteria Research Laboratory (Specific Aim 3). PUBLIC HEALTH RELEVANCE: Multidrug resistant Mycobacterium tuberculosis (MDR-TB) has occurred in hospitals and correctional facilities, and frequently in HIV-infected patient. Clinical responses of MDR- TB patient to currently available drugs have been poor, and in some cases there is no response at all. The long term goal of this grant submission is to develop new drug leads for MDR-TB.