A possible metabolic role foro-diphenoloxidase inMycobacterium leprae

Summary Among mycobacteria,Mycobacterium leprae is unique in its ability to oxidize a variety of diphenols to quinones in vitro. What physiologic roleo-diphenoloxidase has in the organism remained unknown. Reducing substrates like NADPH, NADH and ascorbic acid reacted with the quinone formed from dopa (3,4-dihydroxyphenylalanine); the substrates were oxidized and the quinone was reduced back to diphenol in the process. Since the quinone undergoes reversible oxidation-reduction, diphenoloxidase might serve as an alternative respiratory mechanism inM. leprae for the utilization of other substrates, as has been reported in plants.     

母牛分枝杆菌最佳生长条件的研究

对适宜母牛分枝杆菌 (Mycobacterium vaccae)菌株液体生长的培养基及培养条件进行了研究 ,结果表明在含有 0 .1%的酵母膏培养基中 ,初始 p H7.2 ,培养温度 35℃的条件下有利于母牛分枝杆菌的生长 ,确定为最佳生长条件     

基因功能预测的整合算法及其在结核分枝杆菌基因表达谱分析中的应用

基因功能预测是后基因组时代生物信息学领域的重要课题.生物学机理的阐释需要准确的基因功能的信息,但目前还缺少大规模测定基因功能的实验手段,这使得运用计算方法对基因功能进行预测显得尤为重要,对这些算法的效率和准确性要求也越来越高.在本项研究中开发了一种新的整合算法,将3种比较典型的基于蛋白质序列预测基因功能的算法GOtcha、PFP和conFunc整合起来,并将其应用于结核分枝杆菌的全基因组功能预测中.预测结果通过不同的角度得到了验证,结果表明该整合方法不仅使得基于序列进行基因功能预测的算法可以达到较高的准确度,而且较原来3种方法大幅度提升了预测的性能.另外,预测结果也被用于分析结核分枝杆菌受到卷曲霉素处理前后的基因表达谱,功能富集分析揭示了卷曲霉素新的可能的抗菌作用机制,从而显示出基因功能预测重要的潜在应用价值.     

前脑啡肽原和热休克蛋白参与宿主对结核分枝杆菌感染的应答

利用双向电泳比较了由临床分离的结核分枝杆菌感染离体巨噬细胞U937前后的全细胞蛋白组表达差异，肽指纹鉴定和生物信息学分析2个表达明显上调的斑点．确定它们分别为热休克蛋白HSP105β和前脑啡肽原．比较蛋白质组学和转录组学研究发现，热休克蛋白表达提高可能源于转录增加．提出了从神经免疫学角度研究结核分枝杆菌致病和宿主免疫机理的新思路，为解释吸毒人群中结核病高发病率提供了基础。     

结核疫苗研究进展

目的:回顾卡介苗(BCG)的应用情况,介绍关于结核疫苗研究进展的最新信息。方法:查阅大量关于结核疫苗研究的最近几年的文献。结果:有多种抗结核疫苗正在研究中,例如卡介苗、结核活疫苗、亚单位疫苗、DNA疫苗以及转基因植物疫苗等。结论:BCG仍是目前唯一可应用的抗结核疫苗,但是许多新疫苗己在动物模型中显示出潜力并开始进入临床试验。     

结核分枝杆菌的免疫机制及抗原研究进展

结核分枝杆菌是一种胞内病原苗，在抗结核分枝杆菌感染中，活菌疫苗中的分泌蛋白起主要的免疫保护作用，它们激活宿主Ｔ细胞介导的细胞免疫，影响宿主免疫保护与病菌耐受性之间的不稳定平衡，决定宿主是否得病．结核分枝杆菌的特异性和保护性抗原的筛选为结核病的快速诊断及新型疫苗构建打下基础．     

The surface glycopeptidolipids of mycobacteria: structures and biological properties

One of the most important opportunistic pathogens associated with acquired immunodeficiency syndrome (AIDS) is the M. avium complex. M. avium infections are found in up to 70% of individuals in advanced stages of AIDS. It is apparent that M. avium can replicate in host macrophages and persist for long periods. This group of mycobacteria are distinguished by the presence of unique, highly antigenic, surface-located lipids known as the glycopeptidolipids (GPLs). The GPLs are the chemical basis of the 31 distinct serovars of the M. avium complex, and have also been identified in some other species. The M. avium lipids are immunosuppressive and can induce a variety of cytokines that affect general host responses. Despite extensive chemical characterization of the structures of these GPLs, much work is needed to elucidate the molecular mechanism involved in this complex glycosylation pathway and its genetic basis. The challenges for the future lie in explaining the roles of these copious products in the intracellular life and infectivity of mycobacteria. The intention of our review is to offer a concise account of the structures of the M. avium lipids, their putative roles in the host responses, bacterial physiology and pathogenesis, particularly in immunocompromised patients such as those infected with human immunodeficiency virus (HIV). Advances in chemical synthesis of the various haptenic oligosaccharides are also given to demonstrate how these have helped to define the immunogenic determinants. We believe that future research should involve the creation of conditional mutants defective in these lipids for both functional and biosynthesis studies which will complement biological assays using chemically defined or modified neoglycoconjugates. Received 7 May 2001; received after revision 28 June 2001; accepted 28 June 2001     

结核分枝杆菌和卡介苗抗原蛋白的比较研究

利用Ｗｅｓｔｅｒｎ－Ｂｌｏｔ技术,对结核分枝杆菌和卡介苗抗原蛋白进行研究,发现两个菌种的３１ＫＤ和３０ＫＤ蛋白均能单克隆抗体识别,且两蛋白均存在于培养基滤液中,并对卡介苗诱发抗结核反应的机制进行了探讨。     

表达结核杆菌抗原的重组酿酒酵母免疫小鼠研究

近年来研究显示全细胞重组酿酒酵母疫苗具有治疗性疫苗潜能.为了研究重组酿酒酵母结核病候选疫苗的免疫效果,将IFN-γ基因与结核杆菌抗原蛋白Ag85B、ESAT6的基因融合,利用pHR酿酒酵母表达系统和同源重组方法,成功构建了以酿酒酵母Y16为宿主的表达融合蛋白IF-γ-Ag85B和IF-γ-ESAT6-Ag85B的重组酿...     

Ornithine decarboxylase,S-adenosyl-L-methionine decarboxylase and arginine decarboxylase fromMycobacterium bovis (BCG)

Summary Ornithine decarboxylase (ODC), S-adenosyl-L-methionine decarboxylase (AMDC) and arginine decarboxylase (ADC) activities were detected for the first time in extracts ofMycobacterium bovis (BCG). All the decarboxylases differed from corresponding known bacterial decarboxylases in that: a) ODC did not require GTP for activity; b) ODC was not inhibited by any known inhibitor of bacterial ODCs; c) AMDC and ADC did not require Mg²⁺-ion for activity and were not markedly inhibited by any known inhibitor of the decarboxylases of other bacteria.