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机会性病原体，导致结核病，该病原体负责全球范围内的显着发病率和死亡率。多药耐药性（MDR）菌株的出现和与AIDS相关的结核病感染的出现导致对TB治疗的新有效治疗剂的开发至关重要。腺苷激酶（AK）是结核分枝杆菌的嘌呤打捞途径中的关键酶，最近已被鉴定为负责对结核分枝杆菌活性的一组核苷类似物的生物活化。我们的长期目标是通过利用对结核分枝杆菌的嘌呤挽救途径的特异性抑制来开发新的抗菌剂。我们假设可以利用选择性抑制结核分枝杆菌AK或通过酶对核苷类似物的特异性激活进行利用，以用于MDR结核分枝杆菌感染的治疗干预。该假设基于以下观察结果。 1）纯化的结核分枝杆菌AK磷酸化了一组腺苷类似物，包括2-甲基腺苷，并且需要磷酸化才能使它们的激活具有选择性的活性，以针对结核分枝杆菌。 2）结核分枝杆菌AK与人类同源物具有不到20％的序列身份；因此，其结构可能与人AK的结构显着不同。此外，结核分枝杆菌嘌呤挽救途径并不是任何当前结核病治疗的靶标。因此，对该途径的抑制可能被证明是对MDR-TB的新型治疗干预措施。基于这些观察结果，该提案的实验重点是阐明结核分枝杆菌AK的三维结构，探索酶的结构功能关系，并利用这种关系来发展新的抗菌剂。我们最近确定了结核分枝杆菌AK的晶体结构与腺苷复合物。这种独特的细菌AK的结构揭示了功能二聚体结构，活性位点构象和病原体和人AK之间的活性位点的显着结构差异。我们提出的研究的具体目的是：1）。以不同形式确定结核分枝杆菌AK的晶体结构，以了解参与结核分枝杆菌中腺苷类似物的腺苷磷酸化和生物活化的酶反应机制。 2）使用基于结构和活性的方法结合使用结核分枝杆菌特异性底物和抑制剂。 3）评估铅化合物的生物学活性，并用铅腺苷类似物确定结核分枝杆菌AK的复杂结构。这些研究将为开发抗细菌核苷类似物提供分子基础。