PURCHASE OF A HIGH FIELD NMR SPECTROMETER

购买核磁共振需要资金 以市面上最高的价格运行的光谱仪 磁场。超高场光谱仪将被放置在 在爱荷华大学的高场核磁共振设备中。这是现有的 集中式设施仿照BRS的要求 共享使用资源。博士级别的核磁共振专家和理工科学士。 级别技术人员目前为该设施配备工作人员。广泛的基础 爱荷华大学的核磁共振使用率约为30% 被确定为现有360 MHz活跃用户的研究小组 分光计。这些调查人员将从安装中受益 更高场光谱仪的主要方面是增强的 质子光谱的色散和改进的灵敏度 异核。天然产物的详细结构表征 Products为工具提供了最强有力的理论基础 可能的最高区域。这里介绍的项目包括 天然海洋真菌表皮脂的结构鉴定 肝素衍生的细胞表面低聚糖产品 寡糖、生物碱抗生素、二萜类化合物、抗病毒药物 核苷，以及各种抗肿瘤药物。三个项目是 与蛋白质结构和酶的测定有关 活性部位表征。蛋白质的折叠特性将是 评估来自核糖核酸酶类似物的小肽 还有硫氧还蛋白。肝醇的活性中心化学 脱氢酶将通过高分辨率的研究来探索 组氨酸质子信号。过氧化物酶和其他血红蛋白将 用质子光谱学研究它们的顺磁状态 并通过异核方法，以辨别参与 过氧化氢活化中的血红素区氨基酸。非常高的 场谱仪将被用来评估与场相关的 分子有序化和核弛豫效应的研究 顺磁系统。

Funds are requested for purchase of a nuclear magnetic resonance spectrometer that operates at he highest commercially available magnetic field. The very high field spectrometer will be located in the University of Iowa High Field NMR Facility. This existing centralized facility is modeled after BRS requirements for a shared usage resource. A Ph.D. level NMR specialist and B.S. level technician currently staff the Facility. A broad base of NMR usage exists at the University of Iowa, with some 30 research groups identified as active users of the existing 360 MHz spectrometer. These investigators will benefit from installation of a higher field spectrometer primarily in terms of the enhanced dispersion for proton spectroscopy and the improved sensitivity of heteronuclei. Detailed structural characterization of natural products provides the strongest rationale for an instrument with the highest possible field. Projects described here include structural elucidation of epidermal lipids, marine fungal natural products, cell surface oligosaccharides, heparin-derived oligosaccharides, alkaloid antibiotics, diterpenoids, antiviral nucleosides, and various anti-tumor agents. Three projects are concerned with determination of protein structure and enzyme active site characterization. Protein folding properties will be evaluated for small peptides derived from a ribonuclease analog and from thioredoxin. The active site chemistry of liver alcohol dehydrogenase will be probed through high resolution studies of histidine proton signals. Peroxidases and other hemoproteins will be examined in their paramagnetic states by proton spectroscopy and by heteronuclear methods in order to discern the involvement of heme region amino acids in peroxide activation. The very high field spectrometer will be utilized to evaluate field-dependent effects on molecular ordering and nuclear relaxation in paramagnetic systems.