A new tool to support drug discovery: Native LESA mass spectrometry (NESA)

拟议的研究将开发一种新的分析工具，以支持药物发现。该工具被称为原生液体萃取表面分析（NESA）质谱，结合了两种新兴的质谱技术，并有可能通过解决一个关键挑战，即在生物环境的全部复杂性中进行测量的能力，彻底改变药物发现管道。药物发现是识别新的潜在药物的过程。通常，药物发现涉及针对特定“靶标”（例如，先前已被鉴定为与特定疾病或病症有关的蛋白质）。这种初始筛选产生命中化合物（“命中”），然后对其进行优化以改善其性能。在这个阶段，潜在的药物进入药物开发的临床前阶段，在临床试验之前评估其安全性，毒性和代谢。药物发现的早期阶段非常关注优化靶标和潜在药物之间的相互作用（称为非共价相互作用）。目的是提高结合亲和力，即，加强药物与靶标之间的相互作用，并提高靶标选择性，即，确保药物只与一个目标结合。然而，这些测量是在生理背景之外进行的。这种孤立主义的做法有两个局限性。首先，疾病状态是分子途径的复杂网络的结果，并且药物发现的有效性受到对这些分子途径对药物的反应的不完全理解的阻碍。在完整的生物学背景下测量靶点和药物之间相互作用的能力将改变药物发现的这一方面。其次，在此阶段无法评估药物与其他分子相互作用（“脱靶”效应）产生的安全性和毒理学效应。考虑到药物开发的高损耗率，后者尤为重要。进入临床试验的药物最终进入市场的成功率不到10%。这个阶段失败的首要原因是非临床毒理学。在药物发现过程中早期评估毒理学效应的能力将降低损耗率，并提高药物发现和开发的效率，然而，在生理背景下进行分析测量的能力是物理科学的一个主要挑战，这项工作旨在解决这一挑战。其目的是开发一种分析化学技术- NESA质谱法-用于表征直接来自复杂生物环境（包括血液，组织和细胞）的蛋白质靶标和药物化合物之间的相互作用。广义上讲，质谱是一种分析技术，它提供了高灵敏度，广泛的特异性（所有分子都有质量）和分子结构解析的能力。两种新兴的质谱方法是天然质谱法，其保留非共价相互作用，例如蛋白质靶标和药物之间的相互作用，从而允许它们的询问，以及液体提取表面分析，其允许直接从其实际环境中对分子进行采样。本提案中描述的研究将结合这些令人兴奋的技术，并将其应用于在完整的生物学背景下表征蛋白质-药物相互作用的挑战。

The proposed research will develop a new analytical tool to support drug discovery. The tool, known as native liquid extraction surface analysis (NESA) mass spectrometry, combines two emerging mass spectrometry techniques, and has the potential to revolutionise the drug discovery pipeline by addressing a key challenge, namely the ability to make measurements in the full complexity of the biological environment.Drug discovery is the process whereby new potential medicines are identified. Typically, drug discovery involves initial screening of a library of compounds against a particular 'target' (e.g., a protein that has previously been identified as being involved in a particular illness or disease). This initial screening results in hit compounds ('hits') which are then optimised to improve their performance. At this stage, the potential drug enters the pre-clinical phase of drug development in which its safety, toxicity, and metabolism are assessed prior to clinical trials. The early stages of drug discovery are very much focused on optimising the interactions (known as non-covalent interactions) between the target and the potential drug. The aims are to improve the binding affinity, i.e., strengthen the interaction between the drug and the target, and to improve target selectivity, i.e., ensure the drug binds to one target only. These measurements, however, are made outside of the physiological context. There are two limitations to this isolationist approach. Firstly, disease states are the result of complex networks of molecular pathways, and the effectiveness of drug discovery is hampered by incomplete understanding of the response of those molecular pathways to the drug(s). The ability to measure interactions between the target and drug in the full biological context would transform this facet of drug discovery. Secondly, the safety and toxicological effects resulting from interaction of the drug with other molecules ("off-target" effects) cannot be assessed at this stage. The latter is particularly important when considering the very high attrition rate of drug development. The success rate for a drug entering clinical trials eventually making it to the market is less than 10%. The number one reason for failure at this stage is non-clinical toxicology. The ability to assess toxicological effects earlier in the drug discovery process would reduce attrition rates, and improve the efficiency of drug discovery and development.Nevertheless, the ability to make analytical measurements in the physiological context is a major challenge for the physical sciences, and this work seeks to address that challenge. The aim is to develop an analytical chemistry technique - NESA mass spectrometry - for the characterisation of interactions between protein targets and drug compounds directly from complex biological environments, including blood, tissue and cells. Broadly, mass spectrometry is an analytical technique which offers high sensitivity, broad specificity (all molecules have a mass), and the capability for molecular structure elucidation. Two emerging mass spectrometry approaches are native mass spectrometry, which preserves non-covalent interactions such as those between protein targets and drugs thus allowing their interrogation, and liquid extraction surface analysis, which allows sampling of molecules directly from their actual environment. The research described in this proposal will couple these exciting techniques and apply them to the challenge of characterisation of protein - drug interactions in the full biological context.