BIOCHEMISTRY OF VANADIUM AND IRON

钒和铁的生物化学

• 批准号: 2179157
• 负责人: Alison Butler
• 金额: $ 7.19万
• 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 1997-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2179157
• 关键词: bromine; halogenation; iron metabolism; metal metabolism; metalloenzyme; microorganism metabolism; oxidation; peroxidases; peroxidation; saltwater environment; siderophores; vanadium

The objectives of this research are to improve our understanding of vanadium in biological systems and our understanding of iron in the marine environment. In Part I we are focusing functional biomimetic studies of the essential vanadium ion in vanadium bromoperoxidase (vBrPO; an enzyme isolated from marine algae). V-BrPO is thought to be involved in the biosynthesis of the chiral halogenated and pseudohalogenated natural products, many of which have potent pharmacological activities. Dioxovanadium(V) is the first fully functional mimic of V-BrPO, catalyzing the oxidation of bromide by hydrogen peroxide which results in the formation of brominated organic substrates, or, in the absence of a substrate, the formation of dioxygen. The goal of Part I is to further elucidate the mechanism of the biomimetic system to understand the 10(4) difference in reactivity between V-BrPO it's optimum pH of ca. 6.5 and VO(O2)+ in 0.05 M acid. The approach is to investigate the reactivity of VO(O2)+, vanadium(V) complexes and other transition metal ions complexes towards halide oxidation by hydrogen peroxide, develop chiral halogenation reactions mediated by vanadium and other transition metals and investigate pseudohalogenation reactions mediated by the peroxovanadium(V) system. In Part II, we are focusing on the mechanisms of acquisition of iron (and other metal ions) by open ocean marine bacteria because the discrepancy between iron availability and requirements ranges between 2-5 orders of magnitude and because the transition metal composition of the oceans is extreme and unique. Molybdenum and vanadium are the two most abundant transition metal ions in surface seawater. All microorganisms, with the possible exception of lactobacilli, require iron for growth. It is surprising that so little is known about mechanisms of iron acquisition by marine microorganisms. We are focusing first on the structures of siderophores produced by marine bacteria to determine 1) whether these bacteria produce siderophores that complex iron more tightly than other siderophores, 2) whether their metal binding selectivity is different from terrestrial siderophores and 3) whether the metal uptake mechanisms (metal regulation, pathways, outer membrane proteins) of the marine bacteria differ from terrestrial bacteria.

这项研究的目标是提高我们对 生物系统中的钒和我们对海洋中铁的理解 环境。在第一部分中，我们集中于功能仿生研究 钒溴过氧化物酶（VBRPO；酶）中必需的钒离子 从海洋藻类中分离出来）。 V-BRPO被认为参与了 手性卤素和假钙化天然的生物合成 产品，其中许多具有有效的药理活性。 Dioxovanadium（V）是V-BRPO的第一个功能模仿，催化 过氧化氢对溴化物的氧化，这导致 在没有A的情况下形成溴的有机基材，或 底物，二氧化物的形成。第一部分的目的是进一步 阐明仿生系统的机制了解10（4） V-BRPO之间的反应性差异是Ca的最佳pH值。 6.5和 VO（O2）+在0.05 m酸中。方法是研究 VO（O2）+，钒（V）配合物和其他过渡金属离子配合物 通过过氧化氢朝卤化物氧化，发展手性卤素化 钒和其他过渡金属介导的反应并研究 过氧化物（V）系统介导的假alalagenation反应。在 第二部分，我们专注于获得铁的机制（和 其他金属离子）通过开放海洋细菌，因为差异 铁的可用性和需求之间的范围在2-5个订单之间 大小，因为海洋的过渡金属成分是 极端和独特。钼和钒是最丰富的两个 表面海水中的过渡金属离子。所有微生物， 可能的除乳杆菌外，需要铁才能生长。这是 令人惊讶的是，关于铁的机制知之甚少 海洋微生物。我们首先专注于 海洋细菌生产的铁载体确定1）是否这些 细菌产生的铁载体比其他人更加紧密 铁载体，2）它们的金属结合选择性是否不同于 陆地铁载体和3）金属吸收机制是否（金属）是否 海洋细菌的调节，途径，外膜蛋白） 与陆生细菌不同。