NMR SPECTROSCOPY OF IRON-SULFUR PROTEINS

铁硫蛋白的核磁共振波谱

• 批准号: 6700292
• 负责人: JOHN LUTE MARKLEY
• 金额: $ 25.37万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-02-01 至 2007-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6700292
• 关键词: NMR; SPECTROSCOPY; IRON; SULFUR; PROTEINS

DESCRIPTION (provided by applicant): Work carried out in previous project periods has demonstrated that the combination of NMR spectroscopy, X-ray crystallography, and quantum chemical calculations serves as a highly productive approach to understanding sequence-structure-function relationships in iron-sulfur proteins. NMR spectra contain exquisitely sensitive information about electron nuclear interactions. This information, which is unavailable from X-ray crystal structures, provides insights into the chemical properties of the iron centers, details of their geometry, strengths of hydrogen bonds, and patterns of electron delocalization. NMR thus serves as a window for viewing the properties of the cluster that control redox potentials and regulate pathways of electron transfer. We have shown that high-level quantum chemical approaches can successfully correlate experimental NMR observables with geometric structures provided by high-resolution X-ray crystallography, and thus provide detailed insight to the factors tuning the properties of the metal site. In turn, NMR data and quantum calculations can provide structural constraints in cases where X-ray crystallography has not been feasible at sufficient resolution. We propose to use this coordinated approach to investigate a series of 1Fe and [2Fe-2S] proteins that are model systems in the study of electron transfer, with the aim of answering a number of questions regarding their structure-function relationships. The proteins to be studied include: a series of clostridial rubredoxins (monomeric 1Fe proteins) that have altered redox potentials, desulforedoxin (dimeric 1Fe protein), and four prototypical [2Fe-2S] proteins that have distinct spectral and functional properties (Anabaena vegetative ferredoxin, human ferredoxin, a Rieske protein, and Aquifex aeolicus ferredoxin). We propose, not only to collect and analyze NMR data, but also to collaborate with others to obtain crystal structures and electron-nuclear double resonance (ENDOR) data. An X-ray structure for reduced rubredoxin recently became available, but currently no structures are available for any reduced [2Fe-2S] proteins. Effort will be expended toward improving the calculations for 1Fe proteins and extending the methodology to [2Fe-2S] proteins. Effort will also be expended toward developing new methodology for paramagnetic NMR, in particular, for systems that are not amenable to established approaches.

描述(申请人提供)：在以前的项目期间开展的工作表明，核磁共振光谱、X射线结晶学和量子化学计算的结合是理解铁-硫蛋白质中序列-结构-功能关系的一种高效方法。核磁共振谱包含有关电子和核相互作用的极其敏感的信息。这些信息是从X射线晶体结构中无法获得的，它提供了对铁中心的化学性质、其几何细节、氢键强度和电子离域模式的深入了解。因此，核磁共振是一个窗口，用于查看控制氧化还原电位和调节电子转移路径的团簇的性质。我们已经证明，高水平的量子化学方法可以成功地将实验的核磁共振观测数据与高分辨率X射线结晶学提供的几何结构相关联，从而为调节金属位置的性质的因素提供详细的见解。反过来，核磁共振数据和量子计算可以在X射线结晶学在足够分辨率下不可行的情况下提供结构约束。我们建议使用这种协调的方法来研究一系列1Fe和[2Fe-2S]蛋白质，它们是研究电子转移的模型系统，目的是回答一些关于它们的结构-功能关系的问题。将被研究的蛋白质包括：一系列改变氧化还原电位的梭状红豆蛋白(单体1FE蛋白)、去氧还蛋白(二聚体1FE蛋白)和四种具有不同光谱和功能特性的原型[2FE-2S]蛋白(鱼腥藻营养铁氧还蛋白、人铁氧还蛋白、Rieske蛋白和Aquifex aeolicus Ferredosin)。我们建议，不仅要收集和分析核磁共振数据，而且要与其他人合作获得晶体结构和电子-核双共振(Endor)数据。最近出现了还原Rubredox的X射线结构，但目前还没有任何还原的[2Fe-2S]蛋白质的结构。将努力改进对1Fe蛋白质的计算，并将方法扩展到[2Fe-2S]蛋白质。还将努力为顺磁核磁共振开发新的方法，特别是对于那些不适应现有方法的系统。