SIDEROPHORES AND VIRULENCE OF PSEUDOMONAS AERUGINOSA

这项研究的目的是了解假单胞菌 铜绿假单胞菌获得细胞外铁，以支持生长， 人类感染。 我们的长期目标是利用这种理解 构建抑制生长或杀菌的 化合物. 要成为成功的病原体，铜绿假单胞菌必须 从哺乳动物铁储备中动员铁，血清 转铁蛋白和分泌型乳铁蛋白转化为 可用于细菌代谢。 这种细菌依赖于 三种细胞外产物来动员不可利用的铁。 绿脓菌素是一种还原剂，可以催化去除 Fe（II）来自转铁蛋白。 绿脓菌螯铁蛋白和绿脓菌荧光素（铁载体） 是以可利用的形式提供铁的铁结合化合物 到高亲和力运输系统。 绿脓杆菌素似乎是 最有效的铁载体 第一个具体目标是 建议将遵循铁和绿脓杆菌的命运， 在运输过程中使用放射性标记研究，并比较这些 运输机制与铁绿脓菌螯铁蛋白的运输机制相同。 的 所有三种细胞外产物的协同活动将是 在转运试验期间进行了研究。 高压液相 色谱法（HPLC）和电泳将用于 结合转运试验确定参与 细菌表面和铁中的蛋白水解酶 转铁蛋白的动员。 绿脓菌荧光素的生物合成将 通过分离的色素的氨基酸分析来研究 通过等电聚焦和HPLC，并通过标记 具有放射性氨基酸的绿脓菌荧光素。 突变体产生 铁载体肽部分的缩短片段 将被喂食放射性标记的氨基酸，它们的产物将被 分析以产生肽形成的顺序透视图。 颜料合成的完成将通过以下步骤进行研究： 将（14C）莽草酸酯掺入喹啉衍生物中， 最后转化为绿脓菌荧光素的二羟基喹啉。 NMR和质量 光谱学将被用来分析可能的变化， 绿脓菌荧光素的二羟基喹啉部分。 该信息和 这些化合物将用于我们的研究， 抑制细菌铁的铁载体和前体 采集

The goal is this research is to understand how Pseudomonas aeruginosa obtains extracellular iron to support growth during human infections. Our long-term goal is to use this understanding toward the construction of growth-inhibiting or bactericidal compounds. To be a successful pathogen, P. aeruginosa must mobilize iron from unavailable mammalian iron reserves, serum transferrin and secretory lactoferrin into forms which are available to bacterial metabolism. This bacterium depends upon three extracellular products to mobilize unavailable iron. Pyocyanin is a reducing agent which can catalyze the removal of Fe(II) from transferrin. Pyochelin and pyoverdin (siderophores) are iron binding compounds which supply iron in utilizable forms to high affinity transport systems. Pyoverdin appears to be the most effective siderophore. The first specific aim of this proposal will be to follow the fates of both iron and pyoverdin during transport using radiolabelling studies and to compare these transport mechanisms with those used for ferripyochelin. The concerted activities of all three extracellular products will be investigated during transport assays. High pressure liquid chromatography (HPLC) and electrophoresis will be used in conjunction with transport assays to determine the participation of the bacterial surface and of proteolytic enzymes in iron mobilization from transferrin. The biosynthesis of pyoverdin will be investigated by both amino acid analysis of pigments isolated by isoelectric focusing and HPLC, and by labelling the forms of pyoverdin with radioactive amino acids. Mutants which produce abbreviated segments of the peptide portion of the siderophore will be fed radiolabelled amino acids and their products will be analyzed to yield a sequential perspective of peptide formation. Completion of pigment synthesis will be studied by following the incorporation of (14C)shikimate into the quinoline derivatives and finally into the dihydroxyquinoline of pyoverdin. NMR and mass spectroscopy will be employed to analyze possible alteration in the dihydroxyquinoline moiety of pyoverdin. This information and these compounds will be used in our research for analogues of siderophores and precursors which inhibit bacterial iron acquisition.