新型结核分枝杆菌选择性抑制剂的构效关系及靶点鉴定研究

项目名称： 新型结核分枝杆菌选择性抑制剂的构效关系及靶点鉴定研究

项目编号： No.81473253

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 医药、卫生

项目作者： 罗有福

作者单位： 四川大学

项目金额： 65万元

中文摘要： 耐药结核菌的出现及与HIV病毒的共感染使得结核病的治疗异常困难。基于细胞水平的表型高通量筛选，进而采用化学蛋白组学等正向化学遗传学手段对活性分子的靶点进行鉴定，已成为抗结核治疗新机制及药物发现的有效策略。课题组在对利奈唑胺结构修饰研究中，偶然发现一个双噁唑烷酮化合物，对结核分枝杆菌H37Rv具有选择性抑制活性（MIC=0.125mg/L），这种特点显著区别于已上市的利奈唑胺和处于临床研究阶段的噁唑烷酮类药物的广谱抗菌性质。但它对临床分离的耐药结核菌株出现不同程度的药敏下降，机制尚不清楚。本项目拟对该双噁唑烷酮化合物做结构优化，在寻找对耐药结核菌效果更优的类似物的同时，阐明构效关系，并据此设计合成活性三功能俘获探针分子，开展基于活性的化学蛋白组学研究，结合转录组和基因组分析结果，筛选确认双噁唑烷酮化合物的作用靶点蛋白,分析其选择性机制，为抗结核药物治疗新机制及候选药物发现奠定实验和理论基础。

中文关键词： 双噁唑烷酮；结核分枝杆菌；构效关系；靶点鉴定；化学蛋白组学

英文摘要： The incidence of multidrug-resistant tuberculosis (MDR-TB) and the combined epidemics of HIV and tuberculosis are increasing.This worsening situation make the treatment extremely difficult for patients who are suffering from tuberculosis.Novel antitubercular drug candidates should address such issues as cross-resistance,long-time drug therapy, adverse effects and drug-drug interactions with anti-retrovirus treatment for AIDS. Whole cell-based phenotypic screening has resurged for its high productivity and intrinsic advantages over screening based on biological targets.Forward chemical genetics stratedy like whole genome sequencing offers the possibility of identifying and validating the biological targets of active molecules. In previous study of structural modification of Linezolid, we found a novel bis-oxazolidinone compound which demonstrated excellent and highly selective activities against H37Rv with an MIC value of 0.125mg/L.This property is quite different from the marketed Linezolid and other oxazolidinone drugs in clinical trials. Those oxazolidione drugs possess broad antibacterial spectrum to gram-positive bacteria. However, our compound decreased its potentcy on drug-resistant tuberculosis strains, whose underlying mechanism remained unclear. The present proposal plans to do research work on structure optimization of the hit bis-oxazolidinone compound aiming at improvement of efficacy on the drug-resistant tuberculosis isolates,establishment of the structure -activities relationship, and subsquent design, synthesis and selction of capture compounds for pull-down experiments in the study of chemical proteomics.Furthermore, genome-wide transcriptional analysis of drug treated strains of BCG and H37Rv in different culture conditions, and whole genome sequencing of the mutant strains induced by the active bis-oxazolidinone compounds will be carried out.Canonical correlation analysis will be used to elucidate the protein target(s), their binding mode(s) and drug-resistant machinary. Aslo we would like to analyze the selective mechanism between the species based on our experimental data and the published data, particular those found in NCBI database for gene and protein.

英文关键词： bis-oxazolidinones;M.tuberculosis;Structure-activities relationship;target identification;chemical proteomics