Upgrade to 600 MHz NMR spectrometer

核磁共振（NMR）是一种与磁共振成像（MRI）密切相关的光谱技术。这是一种非常通用的技术。它最大的应用在于它能够提供分子间相互作用的详细信息。高达约30 kDa（250个氨基酸残基）的蛋白质可以快速且几乎自动地分配主链信号。这意味着我们可以快速而简单地计算出哪个信号来自哪个氨基酸，从而提供蛋白质的指纹。配体（例如一种小分子药物或另一种蛋白质）的加入会产生信号的变化，这些变化可以直接分析以确定配体结合的位置，并且通常会产生结合亲和力。对于较大的蛋白质，可以用稍微不同的方法获得类似的信息，尽管需要更多的实验努力。非常大的蛋白质（包括完整细胞中的膜蛋白和受体）仍然可以进行研究，并且有直接的技术可以确定哪些配体与这些靶标结合，以及配体的哪些部分接触最密切。核磁共振还有许多其他用途。它可用于计算溶液中蛋白质的结构，分析局部和全局流动性，观察溶液条件改变或配体添加时的结构变化，测量带电侧链的局部pKa值，分析存在于复杂混合物（如体液）中的代谢物，跟踪代谢和酶促过程，等等。提取此类信息并不总是直截了当的，往往需要专家的建议和干预。目前，我们对一系列目标进行了许多这样的分析，通常是由于外部用户正在调查问题，我们被要求提供建议。项目的选择是基于科学重要性而不是资金，尽管资金显然相当重要。我们目前的设备老旧，变得过时，因此很可能在未来几年的某个时候发生灾难性的故障。我们正在寻求用新设备取代它，这些设备具有非常相似的功能，尽管中间的几年已经导致许多系统的改进，例如更稳定的电子设备和更快速的切换。因此，升级后的仪器将能够像我们现有的仪器一样做同样的事情，但更好、更快，仪器人工制品和限制更少。它将具有一些新的能力，这将使我们能够进行更广泛的调查，并将使它达到最高的国际标准。目前的仪器已经使用了18年，我们预计升级后的仪器至少可以再使用10年，希望能更长。因此，所需的资金是提供世界级核磁共振设施的一个非常具有成本效益的解决方案。升级后的仪器将用于广泛的项目，用户主要来自谢菲尔德，但也有更远的地方。这包括对淀粉样蛋白（阿尔茨海默病的病因）的研究；蛋白质在溶液中的稳定性和溶解度基础研究研究激酶和磷酸化转移酶（代谢途径中的关键调节酶）的机制；研究识别细菌细胞壁特定部分的细菌蛋白质，因此可以用作抗生素和新诊断工具的基础；研究特定蛋白质的功能；以及开发高压核磁共振作为研究相对低群体活性形式的蛋白质的工具。因此，该仪器为生物分子研究中的许多问题提供了重要的资源。

Nuclear Magnetic Resonance (NMR) is a spectroscopic technique closely related to Magnetic Resonance Imaging (MRI). It is a very versatile technique. Its biggest application lies in its ability to provide detailed information on interactions between molecules. Proteins up to about 30 kDa (250 amino acid residues) can have backbone signals assigned rapidly and almost automatically. This means that we can rapidly and simply work out which signal comes from which amino acid, thereby providing a fingerprint of the protein. Addition of a ligand (for example a small molecule drug, or another protein) produces changes in signals, which are straightforwardly analysed to determine where the ligand is binding, and often to produce a binding affinity. With larger proteins, similar information can be obtained in slightly different ways although with rather more experimental effort. Very large proteins (including membrane proteins and receptors in intact cells) are still amenable to investigation, and there are straightforward techniques for identifying which ligands bind to such targets, and which parts of the ligands are most closely in contact. NMR has many other uses. It can be used to calculate the structures of proteins in solution, to analyse local and global mobility, to look at structural change on alteration of solution conditions or addition of ligands, to measure local pKa values of charged sidechains, to analyse the metabolites present in complex mixtures such as body fluids, to follow metabolic and enzymatic processes, and much more. Extracting such information is not always straightforward and often requires expert advice and intervention.Currently we carry out many such analyses on a range of targets, often as a result of problems being investigated by external users that we are asked to advise on. Selection of projects is made on the basis of scientific importance rather than funding, although funding is clearly of considerable importance. Our current equipment is old and becoming obsolete, and is therefore likely to fail catastrophically at some point over the next few years. We are looking to replace it with new equipment, which has very similar capabilities, although the intervening years have led to improvements in many systems, for example more stable electronics and more rapid switching. The upgraded instrument will therefore be able to do the same things as our current instrument, but better and faster, with fewer instrumental artifacts and limitations. It will have some new capabilities, which will enable us to carry out a wider range of investigations, and will bring it up to the highest international standards. The current instrument has lasted 18 years: we expect the upgraded instrument to last at least another 10 and hopefully considerably longer. The funding required is thus a very cost-effective solution to the provision of world-class NMR facilities. The upgraded instrument will be used for a wide range of projects, with users mainly from Sheffield but also further afield. These include investigation of amyloid proteins (the cause of Alzheimer's disease); fundamental research on protein stability and solubility in solution; work on the mechanism of kinases and phosphoryl transferases (key regulatory enzymes within metabolic pathways; investigations on bacterial proteins that recognise specific parts of bacterial cell walls and could therefore be used as a basis for both antibiotics and novel diagnostic tools; investigations of the function of specific proteins; and the development of high-pressure NMR as a tool for investigating the relatively low-population active forms of proteins. The instrument therefore provides an important resource for many problems in biomolecular research.