Protein structure and function studied by NMR

More than 10 years of research in the Laboratory of Nuclear Magnetic Resonance (NMR) at the School of Life Science, University of Science and Technology of China is reviewed. Our researches have focused on two systems: proteins related to the regulation of gene expression in humans and other eukaryotes, and proteins existing in the cell junction in humans. The majority of proteins selected from these two systems are related to human health and diseases, and some are potential drug targets. We were interested in using NMR to study structural basis of protein-protein interactions. NMR was highly suited for investigating molecular interactions under approximately physiological conditions and was particularly suited for the study of low-affinity, transient complexes. It can provide information of protein interaction surface, complex structure, and dynamic properties during protein recognition. Several examples were given in this paper. NMR was also used to study dynamic properties of protein both in pico-second to nano-second and in micro-second to mili-second time scales. We have studied protein folding and unfolding by NMR together with fluorescence and circular dichroism experiments. Proteins in unfolded states were characterized in detail by NMR. The last example of NMR application is the identification of a novel inhibitor of a human dual-specific phosphatase and the cellular effects of this compound were also studied. Our results demonstrate that our screening strategy, which combines both virtual and NMR-based methods, is feasible and might be employed in the early stage of drug discovery.