M. tuberculosis Adenosine Kinase and Design of Antimicrobial Nucleoside Analogs

结核分枝杆菌腺苷激酶和抗菌核苷类似物的设计

基本信息

批准号：
7619128
负责人：
RONGBAO LI
金额：
$ 35.09万
依托单位：
SOUTHERN RESEARCH INSTITUTE
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-05-01 至 2011-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7619128
关键词：
2-methyladenosine Active Sites Adenosine Adenosine Kinase Adenosine Monophosphate Amino Acid Sequence Antibiotics Antimycobacterial Agents Apoenzymes Binding Biochemistry Biological Biological Assay Catalysis Cells Chemicals Collaborations Complex Databases Developed Countries Developing Countries Development Docking Drug Resistant Tuberculosis Drug resistance in tuberculosis Enzymes Foundations Goals HIV Homologous Gene Human Infection Intervention Joints Laboratories Lead Ligand Binding Ligands Modeling Modification Molecular Molecular Conformation Morbidity - disease rate Multi-Drug Resistance Mycobacterium tuberculosis Nucleosides Outcome Study Pathway interactions Peptide Sequence Determination Pharmaceutical Chemistry Phase Phosphorylation Phosphotransferases Principal Investigator Procedures Prodrugs Protein Binding Proteins Purines Reaction Research Research Institute Research Personnel Resolution Resources Role Screening procedure Sequence Alignment Structural Models Structure Structure-Activity Relationship Substrate Specificity Techniques Testing Therapeutic Agents Therapeutic Intervention Time Tuberculosis Virtual Library World Health Organization adenosine monophosphate-adenosine analog antimicrobial base clinical application computational chemistry cytotoxic database design design dimer enzyme activity enzyme structure inhibitor/antagonist inorganic phosphate insight killings mortality mutant mycobacterial novel novel therapeutic intervention novel therapeutics nucleoside analog pathogen programs protein structure public health emergency purine purine analog purine metabolism receptor resistant strain small molecule libraries structural biology therapeutic development three dimensional structure tuberculosis drugs tuberculosis treatment virtual

项目摘要

DESCRIPTION (provided by applicant): Mycobacterium tuberculosis is an opportunistic pathogen that causes TB, which is responsible for significant morbidity and mortality worldwide. The emergence of multi-drug resistance (MDR) strains and the AIDS-associated TB infection has led to a critical need for the development of new and effective therapeutic agents for the TB treatment. Adenosine kinase (AK) is a key enzyme in the purine salvage pathway of M. tuberculosis and has recently been identified to be responsible for the bioactivation of a group of nucleoside analogs that are active against M. tuberculosis. Our long term goal is to develop new antimycobacterial agents by exploiting specific inhibition of the purine salvage pathway in M. tuberculosis. We hypothesize that selective inhibition of M. tuberculosis AK or specific activation of nucleoside analogs by the enzyme can be exploited for therapeutic intervention of MDR M. tuberculosis infection. This hypothesis is based on the following observations. 1) Purified M. tuberculosis AK phosphorylated a group of adenosine analogs, including 2-methyladenosine, and the phosphorylation is required for their activation to become selectively active against M. tuberculosis. 2) M. tuberculosis AK share less than 20% sequence identity with the human homolog; therefore, its structure is likely to be significantly different from that of human AK. In addition, the M. tuberculosis purine salvage pathway is not the target of any current TB therapy; therefore, inhibition of this pathway may prove to be a novel therapeutic intervention to MDR-TB. Based on these observations, the experimental focus of this proposal is to unravel the three-dimensional structure of M. tuberculosis AK, explore the structure function relationship of the enzyme, and exploit this relationship for the development of new antimycobacterial agents. We have recently determined the crystal structure of M. tuberculosis AK in complex with adenosine. The structure of this unique bacterial AK revealed a functional dimer structure, the active site conformation and significant structural differences in the active sites between the pathogen and human AK. Our specific aims of this proposed research are: 1). to determine the crystal structure of M. tuberculosis AK in different forms for understanding the enzyme reaction mechanism involved in adenosine phosphorylation and bioactivation of adenosine analogs in M. tuberculosis. 2) To identify M. tuberculosis -specific substrates and inhibitors of AK using a combination of structure- and activity-based approaches. 3) To evaluate the biological activities of the lead compounds and determine the complex structure of M. tuberculosis AK with a lead adenosine analog. These studies will provide molecular basis for development of anti-mycobacterial nucleoside analogs.

描述（由申请人提供）：结核分枝杆菌是一种引起结核病的机会性病原体，是造成全世界显着发病率和死亡率的原因。多重耐药（MDR）菌株和艾滋病相关结核感染的出现导致迫切需要开发新的有效的结核治疗药物。腺苷激酶 (AK) 是结核分枝杆菌嘌呤补救途径中的关键酶，最近已被确定负责一组具有抗结核分枝杆菌活性的核苷类似物的生物激活。我们的长期目标是通过利用结核分枝杆菌中嘌呤补救途径的特异性抑制来开发新的抗分枝杆菌药物。我们假设选择性抑制结核分枝杆菌 AK 或通过酶特异性激活核苷类似物可用于治疗性干预 MDR 结核分枝杆菌感染。该假设基于以下观察。 1) 纯化的结核分枝杆菌 AK 磷酸化一组腺苷类似物，包括 2-甲基腺苷，并且磷酸化是它们激活以选择性地对抗结核分枝杆菌的活性所必需的。 2) 结核分枝杆菌AK与人类同源物的序列同一性低于20%；因此，它的结构很可能与人类AK有显着不同。此外，结核分枝杆菌嘌呤补救途径不是任何当前结核病治疗的目标；因此，抑制该途径可能被证明是耐多药结核病的一种新的治疗干预措施。基于这些观察，本提案的实验重点是揭示结核分枝杆菌AK的三维结构，探索酶的结构功能关系，并利用这种关系开发新型抗分枝杆菌药物。我们最近确定了结核分枝杆菌 AK 与腺苷复合物的晶体结构。这种独特的细菌 AK 的结构揭示了功能性二聚体结构、活性位点构象以及病原体和人类 AK 之间活性位点的显着结构差异。我们这项拟议研究的具体目标是：1）。确定不同形式的结核分枝杆菌AK的晶体结构，以了解结核分枝杆菌中腺苷磷酸化和腺苷类似物生物活化所涉及的酶反应机制。 2) 结合基于结构和活性的方法来鉴定 AK 的结核分枝杆菌特异性底物和抑制剂。 3) 评估先导化合物的生物活性并确定结核分枝杆菌AK与先导腺苷类似物的复杂结构。这些研究将为抗分枝杆菌核苷类似物的开发提供分子基础。