In this paper, we discuss methods for determining structures of protein-ligand complexes by NMR in solution. Our discussion is based on small ligands (<2 kDa) as for example drugs, metabolites or oligo-peptides, but most of the considerations also apply to more general cases. In NMR in solution, the kinetics of association and dissociation of the complex - the exchange rate - determines the optimal sample preparation and the NMR experimental approach. Additionally, depending on the part of the complex that will be studied (only the bound ligand, the protein, the protein-ligand interface or the entire protein-ligand complex structure), different types of NMR experiments are needed. Therefore, the choice of a combination of the appropriate experiment and a suitable sample preparation in terms of ligand to protein ratios are discussed in detail. Also, considerations for practically preparing samples of protein-ligand complexes and carrying out experiments including trouble shooting are described. For structure determination, the scope of this paper is limited to NOE-based methods and some of the most recent approaches will be covered.

中文翻译：

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溶液中蛋白质配体复合物的 NMR 结构测定

在本文中，我们讨论了通过 NMR 在溶液中确定蛋白质-配体复合物结构的方法。我们的讨论基于小配体 (<2 kDa)，例如药物、代谢物或寡肽，但大多数考虑也适用于更一般的情况。在溶液中的 NMR 中，复合物的缔合和解离动力学 - 交换率 - 决定了最佳的样品制备和 NMR 实验方法。此外，根据将要研究的复合物部分（仅结合配体、蛋白质、蛋白质-配体界面或整个蛋白质-配体复合物结构），需要进行不同类型的 NMR 实验。因此，详细讨论了在配体与蛋白质比率方面选择合适的实验和合适的样品制备的组合。此外，还描述了实际制备蛋白质配体复合物样品和进行包括故障排除在内的实验的考虑因素。对于结构确定，本文的范围仅限于基于 NOE 的方法，并且将涵盖一些最新的方法。