ACQUISITION OF CRYOPROBE FOR 600 MHZ NMR SPECTROMETER

目前，600 MHz的核磁共振时间是伊利诺伊大学芝加哥分校(UIC)几个严重依赖核磁共振的NIH资助项目进度的限制因素。这种情况将因预期的项目扩展和最近招募的另一名核磁共振光谱仪而加剧。为了经济高效地增加用于UIC结构生物学的Bruker 600 MHz核磁共振光谱仪的可用核磁共振仪器时间，建议为该光谱仪购买一个反向检测、三重共振、z梯度5 mm低温探头。这种低温探头目前正在开发中，预计将在本提案的资助期内投入商业使用。低温探头已经成功地在较低的磁场中开发出来，并可用于500 MHz光谱仪。根据制造商在500 MHz含盐水样品上的结果，600 MHz低温探头的信噪比预计至少比室温下使用线圈和前置放大器的同等探头提高2.4。这将使数据获取时间节省5.8倍，因此相当于以这种购买费用的一小部分额外购买一台以上的600兆赫光谱仪。代表600 MHz光谱仪主要用户的四个研究小组将立即从这项探测中受益，他们是医学院的迈克尔·卡弗里、廖秀北和彼得·盖廷斯，以及药学院的迈克尔·约翰逊，他们与罗约拉大学的莱斯利·冯合作。所有的研究项目都使用核磁共振来调查生物医学研究问题。卡弗里博士最近加入了UIC，正在研究与细胞感染有关的病毒蛋白的核磁共振结构。廖博士有一个建立在核磁共振基础上的研究项目，用来检测一系列“有翼螺旋”转录因子与DNA结合的特异性。约翰逊博士和冯博士正在使用核磁共振技术来确定血影蛋白结构域的结构，这是一种构成红细胞膜支架的蛋白质。Gettins博士正在使用核磁共振来确定低密度脂蛋白受体家族蛋白质的结构域以及与这些受体结合的蛋白质配体的结构。另外三个研究小组将在与盖廷斯博士的合作项目中，作为次要用户受益。他们是奥尔森博士，他对丝氨酸抑制机制感兴趣；帕斯顿博士，他对丝氨酸血管紧张素原的结构感兴趣；西尔弗博士，他正在研究一种独特的银结合蛋白--SILE。

Availability of NMR time at 600MHz is currently a limiting factor in the rate of progress of several heavily NMR-dependent NIH-funded projects at the University of Illinois at Chicago (UIC). This situation will be exacerbated by anticipated project expansion and by the recent recruitment of another NMR spectroscopist. To cost-effectively increase the available NMR instrument time on a Bruker 600MHz NMR spectrometer that is used for structural biology at UIC, it is proposed to purchase an inverse detection, triple resonance, z-gradient 5mm cryoprobe for the spectrometer. Such a cryoprobe is currently under development, and is expected to be commercially available during the funding period of this proposal. Cryoprobes have already been successfully developed at lower fields and are commercially available for 500MHz spectrometers. Based on the manufacturer's results on salt- containing aqueous samples at 500MHz, an improvement in signal-to-- noise of at least 2.4 is expected for the 600MHz cryoprobe over an equivalent probe operating with coils and preamplifier at room temperature. This would result in a saving in time for data acquisition of 5.8-fold and consequently would represent the equivalent of acquiring more than one additional 600MHz spectrometer at a fraction of the cost of such a purchase. Four research groups, that represent the primary users of the 600MHz spectrometer, will derive immediate benefit from this probe, those of Michael Caffrey, Xiubei Liao and Peter Gettins in the College of Medicine and Michael Johnson in the College of Pharmacy, in collaboration with Leslie Fung at Loyola University. All have research projects that use NMR to investigate biomedical research problems. Dr. Caffrey recently joined UIC and is working on NMR structural studies of viral proteins involved in cell infection. Dr. Liao has an established NMR-based research program examining the specificity of DNA binding by a family of "winged helix" transcription factors. Dr. Johnson and Dr. Fung are using NMR to determine the structure of the domains of spectrin, a protein that forms part of the scaffold of the red blood cell membrane. Dr. Gettins is using NMR to determine the structures of domains from proteins of the LDL receptor family and of protein ligands that bind to these receptors. Three other research groups will benefit as minor users, in collaborative projects with Dr. Gettins. These are Dr. Olson, with interests in serpin inhibition mechanism, Dr. Patston, with interests in the structure of the serpin angiotensinogen, and Dr. Silver, who is characterizing a unique silver binding protein, silE.