NMR line shapes and multi-state binding equilibria
NMR line shapes and multi-state binding equilibria
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DOI：
10.1007/s10858-012-9636-3
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发表时间：
2012-07-01
影响因子：
2.7
通讯作者：
Kovrigin, Evgenii L.
中科院分区：
文献类型：
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作者：
Kovrigin, Evgenii L.
蛋白质的生物学功能依赖于构象转变和特异性配体的结合。蛋白质-配体相互作用在分子动力学和分子动力学上与蛋白质结构的构象变化相耦合，如通过预先存在的平衡和诱导拟合模型所概念化的。NMR光谱对复杂的配体结合模式特别敏感，NMR线形分析可以提供具有位点特异性分辨率的配体结合平衡的热力学和动力学常数。然而，广泛使用的线型分析受到阻碍的复杂性NMR线形状在多状态系统。为了便于解释这样的光谱模式，我计算探索系统中的异构化或二聚化的蛋白质（受体）分子耦合到结合的配体。通过对一个三态模型家族的多个交换机制的广泛分析，我确定了签名特征，以指导NMR实验人员识别特定的相互作用机制。结果表明，不同的多状态模型可能会产生非常相似的光谱模式。我还讨论了受体的聚集作为虚假的三态线形的可能来源，并提供了补充实验，可以确保可靠的机制洞察力的具体建议。
Biological function of proteins relies on conformational transitions and binding of specific ligands. Protein-ligand interactions are thermodynamically and kinetically coupled to conformational changes in protein structures as conceptualized by the models of pre-existing equilibria and induced fit. NMR spectroscopy is particularly sensitive to complex ligand-binding modes-NMR line-shape analysis can provide for thermodynamic and kinetic constants of ligand-binding equilibria with the site-specific resolution. However, broad use of line shape analysis is hampered by complexity of NMR line shapes in multi-state systems. To facilitate interpretation of such spectral patterns, I computationally explored systems where isomerization or dimerization of a protein (receptor) molecule is coupled to binding of a ligand. Through an extensive analysis of multiple exchange regimes for a family of three-state models, I identified signature features to guide an NMR experimentalist in recognizing specific interaction mechanisms. Results show that distinct multi-state models may produce very similar spectral patterns. I also discussed aggregation of a receptor as a possible source of spurious three-state line shapes and provided specific suggestions for complementary experiments that can ensure reliable mechanistic insight.