ACQUISITION OF CRYOPROBE FOR 600 MHZ NMR SPECTROMETER

目前，在芝加哥的伊利诺斯大学（UIC），NMR时间的可用性是几个严重依赖NMR的NIH资助项目进展速度的限制因素。由于预期的项目扩大和最近征聘了另一名核磁共振波谱师，这种情况将进一步恶化。为了经济有效地增加用于UIC结构生物学的Bruker 600 MHz NMR光谱仪的可用NMR仪器时间，建议为光谱仪购买反向检测、三重共振、z梯度5 mm冷冻探针。这种冷冻探针目前正在开发中，预计将在本提案的供资期内投入商业使用。低温探针已经在较低的磁场下成功开发，并可用于500 MHz光谱仪。根据制造商在500 MHz下对含盐水性样品的结果，预期600 MHz冷冻探针的信噪比至少比在室温下使用线圈和线圈的等效探针提高2.4。这将节省5.8倍的数据采集时间，因此相当于以这种购买成本的一小部分购买一个以上的额外600 MHz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该探测器中受益，他们是医学院的Michael Caffrey，Xiubei Liao和Peter Gettins以及药学院的Michael约翰逊，与Loyola大学的Leslie Fung合作。他们都有使用核磁共振研究生物医学研究问题的研究项目。Caffrey博士最近加入了UIC，并致力于参与细胞感染的病毒蛋白质的NMR结构研究。廖博士有一个建立的基于核磁共振的研究计划，检查DNA结合的特异性由一个家庭的“翼螺旋”转录因子。约翰逊博士和冯博士正在使用核磁共振来确定血影蛋白结构域的结构，血影蛋白是一种形成红细胞膜支架的蛋白质。Gettins博士正在使用NMR来确定LDL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域。其他三个研究小组将作为次要用户与Gettins博士合作项目受益。他们是奥尔森博士，对丝氨酸蛋白酶抑制机制感兴趣，帕斯顿博士，对丝氨酸蛋白酶抑制剂血管紧张素原的结构感兴趣，以及银博士，他正在描述一种独特的银结合蛋白思乐。

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.