Label-free Protein Analysis Methods for Active Compound Targets Identification

As more and more active ingredients are discovered, there is an increasing demand to explore the pharmacological mechanisms of these drugs and identify their effective targets. Chemical biology, as a newly developed interdisciplinary field in recent years, is the best choice to undertake this task. The identification method of unlabeled targets does not involve any chemical modification of small molecular drugs and has attracted wide attention in recent years. Most of the target identification methods based on interaction belong to the type of unlabeled deconvolution. Label-free protein analysis can also help predict potential drug targets or candidates, develop new biomarker assays and diagnostic reagents, and evaluate the selectivity and range of active compounds to reduce the risk of off-target effects. It can achieve these goals using techniques such as changing protein thermal stability, enzyme sensitivity, and molecular structure and using mass spectrometry. In this paper, we review the reported Label-free protein analysis techniques for identifying different types of targets. Based on different principles from three perspectives, hydrogen deuterium exchange mass spectrometry, surface plasmon resonance, microscale thermophoresis, fluorescence correlation spectroscopy, and other techniques are introduced, and the principles and scope of application of these techniques are introduced to readers through figures, texts, and tables. The combined use of various techniques can improve the success rate of target discovery, but this review still has the limitation of incomplete summary of the techniques. To give the reader an initial impression of Label-free protein analysis techniques that can provide valuable insights for drug target discovery. The target identification of active compounds can deepen our understanding of the mode of action of clinical drugs, help to discover new undruggable proteins, and provide the possibility for innovative treatments. With the development of mass spectrometry-based proteomics and computational biology, it can provide more help and possibility for us to explore the targets of active compounds. The popularization of these techniques can provide more options for researchers and facilitate the improvement of drug properties.