THE BIOINORGANIC CHEMISTRY OF IRON

铁的生物无机化学

• 批准号: 6266870
• 负责人: Alison Butler
• 金额: $ 24.22万
• 依托单位: UNIVERSITY OF CALIFORNIA SANTA BARBARA
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-02-01 至 2005-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6266870
• 关键词: Mycobacterium; aminoacid; amphiphilicity; aquatic organism; atomic force microscopy; cryoelectron microscopy; electron crystallography; freeze etching; halogenation; ion transport; iron metabolism; light scattering; mass spectrometry; membrane proteins; metal metabolism; metalloenzyme; microorganism metabolism; nuclear magnetic resonance spectroscopy; peroxidases; saltwater environment; siderophores; ultracentrifugation; vanadium

DESCRIPTION (Adapted from applicant's abstract): The objectives of this research are to improve our understanding of the mechanisms of metal acquisition by microorganisms in the marine environment. Interest in the mechanisms of acquisition of iron (and other metal ions) by oceanic bacteria derives from the unique transition metal ion composition of the ocean and the discrepancy between iron availability and requirements. Iron is a limiting nutrient to marine microorganisms over much of the world's oceans at a concentration of 0.02-1 nM in surface seawater, whereas molybdenum and vanadium are the two most abundant transition metal ions at 100 nM and 20-35 nM, respectively. In the previous grant period the Principal Investigator discovered a new class of self-assembling amphiphilic peptide siderophores, the marinobactins and aquachelins, produced by two phylogenetically distinct genera within the marine gamma proteobacteria. The only siderophores which bear a structural resemblance to the marinobactins and aquachelins are the amphiphilic mycobactin and exochelin siderophores. These siderophores are produced by mycobacteria, such as Mycobacterium tuberculosis, the bacterium causing tuberculosis. Little is known about the molecular mechanism of pathogenesis of M. tuberculosis, however, its capacity to infect the host is closely linked to its ability to acquire iron. The specific aims of the proposed research include I) further characterization of the amphiphilic marine siderophores and the mycobactins, II) further investigations of the Alteromonas luteoviolacea system, the marine bacterium which produces the alterobactin siderophores and III) the isolation and structural characterization of siderophores produced by other oceanic bacteria. These studies are the first part of an investigation into whether the mechanisms of iron acquisition (e.g., siderophore-mediated sequestration of the iron, outer membrane receptor protein recognition of the metal siderophore complex, transport, and metal regulation of these processes, etc.) by marine bacteria differ from terrestrial bacteria.

描述（改编自申请人的摘要）：此目的 研究是为了提高我们对金属机制的理解 在海洋环境中通过微生物获取。对 海洋细菌获取铁（和其他金属离子）的机制 源自海洋和海洋独特的过渡金属离子组成 铁的可用性和要求之间的差异。铁是一个限制 在世界上大部分海洋上，海洋微生物的养分 地表海水中的0.02-1 nm浓度，而钼和钒浓度 是100 nm和20-35 nm处的两个最丰富的过渡金属离子， 分别。在上一个赠款期间，首席调查员 发现了一类新的自组装两亲性肽铁载体， Marinobactins和Aquachelins，由两个系统发育不同的属产生 在海洋γ蛋白杆菌中。唯一带有A 与Marinobactins和Aquachelins的结构相似 霉菌蛋白和外胆素铁载体。这些铁载体是由 分枝杆菌，例如结核分枝杆菌，细菌引起 结核。关于发病机理的分子机制知之甚少 然而，结核病分枝杆菌感染了宿主的能力与 它获得铁的能力。拟议研究的具体目的包括 i）进一步表征两亲的海洋铁载体和 Mycobactins，ii）进一步研究Alteromonas leteoviolacea 系统，产生拟跨双子素铁载体的海洋细菌和 iii）由 其他海洋细菌。这些研究是调查的第一部分 涉及铁采集的机制（例如，铁载体介导 铁，外膜受体蛋白识别的隔离 金属铁载体复合物，这些过程的转运和金属调节， 等）海洋细菌与陆生细菌不同。