M. tuberculosis Cell Wall Biogenesis; New Drugs; TB-HIV

描述(由申请人提供)： 自艾滋病流行开始以来，全球艾滋病毒相关结核病的发病率一直在上升，预计未来还会进一步上升，特别是在发展中国家。艾滋病毒感染的加速和放大影响正在导致结核分枝杆菌耐多药菌株引起的疾病发病率上升。因此，开发治疗结核病的新药对控制这两种感染都很重要。由于分枝杆菌细胞壁在分枝杆菌表面形成保护性的、几乎不渗透的屏障，因此它是抗结核药物设计的一个有吸引力的靶点。目前用于治疗结核病的一些最有效的药物会影响其主干成分--支链霉菌半乳糖-肽多聚糖(MAGP)复合体。我们的长期目标是确定mAGP组装所涉及的过程和酶。最近在结核分枝杆菌基因组中发现了可能的AG生物合成基因簇，因此这项资助计划的具体目的是：1.在AG生物合成簇中鉴定参与分枝杆菌半乳糖生物合成的基因，并通过克隆、过表达和随后的生化特征确定它们的生物学功能。2.通过突变体/条件突变体的制备和表型鉴定，确定ABC转运蛋白在AG生物合成簇中的功能。该方法将有助于定义微生物生物化学中更复杂的途径之一，并揭示应该用于药物开发的反应。这项研究将主要在斯洛伐克布拉迪斯拉发的夸美纽斯大学自然科学学院与卡塔琳娜·米库索娃合作进行，作为国家卫生研究院A1-18357号补助金的延伸。

DESCRIPTION (provided by applicant): The incidence of HIV-associated tuberculosis has been increasing worldwide since the beginning of the AIDS epidemic, and is expected to rise even further in the future, especially in developing countries. The accelerating and amplifying influence of HIV infection is contributing to the increasing incidence of disease caused by multidrug-resistant strains of Mycobacterium tuberculosis. Development of new drugs against tuberculosis is thus important for control of both of the infections. Mycobacterial cell wall is an attractive target for rational drug design against tuberculosis, due to the fact that it forms a protective, almost impermeable barrier, on the surface of mycobacteria. Some of the most effective drugs currently used for the treatment of TB affect components of its backbone - mycolylarabinogalactan-peptidoglycan (mAGP) complex. Our long-term goal is to identify processes and enzymes involved in the mAGP assembly. Possible AG biosynthetic gene cluster has been recently identified in the genome of M. tuberculosis and thus the specific aims of this grant proposal are: 1. Identify the genes involved in mycobacterial galactan biosynthesis within AG biosynthetic cluster and determine their biological functions via cloning, overexpression and subsequent biochemical characterization. 2. Establish the function of the putative ABC transporter within the AG biosynthetic cluster by way of preparation and phenotypic characterization of the mutants/conditional mutants. The approach will help define one of the more complex pathways in microbial biochemistry and reveal reactions that should be exploitable for drug development. The research will be primarily carried out at Comenius University, Faculty of Natural Sciences in Bratislava, Slovakia in collaboration with Katarina Mikusova, as an extension of the NIH grant A1-18357.