结核分枝杆菌DNA修复fpg基因克隆表达及性质研究

发布时间：2018-06-21 06:27

本文选题：DNA损伤 + 碱基切除修复　；参考：《西南大学》2010年硕士论文

【摘要】： 目前结核病仍然是全球人类健康的主要威胁,原发性耐药在耐药结核病产生中占主导地位。全球约有17-20亿的人感染结核分枝杆菌(Mycobacterium tuberculosis,即结核菌或M.tuberculosis),病人约有2000万,每年感染M.tuberculosis的患者有约3000万,在800万的新患者中,约200万死于该病。近几年间,我们不断加大结核病,疟疾以及艾滋病这三大疾病的处理力度,在世界卫生组织公布的22个限制结核控制成效的高负担国中,中国和印度已成为结核病最多的两个国家。M. tuberculosis的潜伏感染直接导致了结核病治疗疗程长,疗效差,以及化疗后易复发等,因为疗程长,不能负担所需的医疗费用,病人不能充分化疗,这也是结核病高复发率及耐药病例增多的原因,同时也是结核病难治愈的原因。维持基因组稳定是生物生存的基础。碱基切除修复(Base Excision Repair, BER)是DNA修复的主要方式之一。碱基切除修复对结核分枝杆菌等胞内致病菌尤其重要。fpg是碱基切除修复的关键酶。通过比较分枝杆菌的基因组,发现结核菌较其他非致病分枝杆菌普遍具有碱基切除修复基因。这提示碱基切除修复可能与结核菌在宿主体内存活和致病有关。这条途径也许是新结核病药物研发的重要靶标。本研究针对此现状,在大肠杆菌中克隆表达结核分枝杆菌H37Rv -fpg,再经IPTG诱导,Ni2+ Sepharose纯化重组蛋白,针对该蛋白开展进一步的研究,以期得到相关的信息。论文还比较了重组菌和空载转化菌株对双氧水和UV辐射的抗性,探讨了结核菌fpg基因在其中的功能。
[Abstract]:At present, tuberculosis is still a major threat to global human health, and primary drug resistance plays a leading role in the development of drug resistant tuberculosis. About 17-2 billion people worldwide are infected with Mycobacterium tuberculosis-Mycobacterium tuberculosis.There are about 20 million patients infected with Mycobacterium tuberculosus and 30 million patients infected with M. tuberculosis each year, and about 2 million of the 8 million new patients die of the disease. In recent years, we have been increasing our efforts to address the three major diseases of tuberculosis, malaria and AIDS, among the 22 high-burden countries that the World Health Organization has announced to limit the effectiveness of TB control. China and India have become the two countries with the largest number of TB cases. The latent infection of M. tuberculosis has directly resulted in long course of treatment, poor curative effect, and easy recurrence after chemotherapy, because the course of treatment is too long to afford the necessary medical expenses. Insufficient chemotherapy is the reason for the high recurrence rate of TB and the increase of drug resistant cases, as well as the difficult cure for TB. Maintaining genomic stability is the basis of biological survival. Base excision repair (ber) is one of the main methods of DNA repair. Base excision repair is especially important for mycobacterium tuberculosis and other intracellular pathogens. FPG is the key enzyme of base excision repair. By comparing the genomes of Mycobacterium spp., it was found that Mycobacterium tuberculosis had the base excision repair gene more commonly than other non-pathogenic mycobacteria. This suggests that base excision and repair may be related to the survival and pathogenicity of tuberculous bacteria in the host. This approach may be an important target for the development of new TB drugs. In this study, Mycobacterium tuberculosis H37Rv-fpgwas cloned and expressed in Escherichia coli, and then purified by IPTG induced Ni2 Sepharose. Further research on the recombinant protein was carried out in order to obtain relevant information. The resistance to hydrogen peroxide and UV radiation of recombinant and no-load transformed strains were compared, and the function of fpg gene of tuberculous bacillus was discussed.
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：R378

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