Research And Discovery Of New Anti-tb Lead Compounds And Drug Targets

Tuberculosis remains the major global threat to human health, with 8 million cases of clinical tuberculosis and 3 million deaths annually. Mycobacterium tuberculosis (MTB) is the causative agent of tuberculosis. The emergence of multi-drug resistant strains of MTB and co-infection with the human immunodeficiency virus(HIV) have further emphasized the need for effective prevention and treatment of tuberculosis. According to WHO, the DOTS therapeutic methods are recommended to control TB though it is not suitable for MDR-TB or XDR-TB. It consists of 2 month's treatment with four so-called first-line drugs including rifampin (RIF), isoniazid (INH), pyrazinamide (PZA) and ethambutol (EMB), followed by 4 months' treatment with RIF and INH. Due to the impractically long period of more than 6 months, it's difficult for those patients to insist the treatment till end. So it's important to find out more specific and effective drugs to solve these current problems.Our lab syntheses a new leading compound toward MTB on the basis of high-throughput techniques named S28, which showed excellent anti-TB activities in the experiments in vitro. But we didn't yet clarify its drug targets. Depending on the techniques of two dimensional electrophoresis and MALDI-TOF-MS, using comparative proteome method, we tried to analyze the possible differences and lead our research to the right direction. Two dimensional gel electrophoresis (2-DE) was employed to address this problem and global proteome of H₃₇Ra untreated and treated with S28 were compared. 13 protein spots were found to be expressed decreased. 6 protein spots which remarkably decreased in Mycobacterium tuberculosis treated with S28 were subjected to matrix assisted laser adsorption ionization time of flight mass spectrometry (MALDI- TOF-MS) analysis and 3 protein spots were determined successfully. The 3 protein spots in gel were identified as elongation factor Tu, short chain dehydrogenase and Rv2626c, which play important roles in protein translation and energy metabolism. These data provide insights into the potential novel anti-tuberculosis mechanism and drug targets.Rv2626c is a hypothetical conserved protein whose function is unkown as a member of Hypoxia Response Protein Family. The protein is expressed in high level under low oxygen concentration, which indicates its possible potential functions in TB latent condition. The expression level of Rv2626c decreased evidently when TB was treated with S28. To explore its possible functions, Rv2626c was cloned, expressed and purified, which paved the way to the furure research.