NMR analysis of carbohydrate-protein interactions
NMR analysis of carbohydrate-protein interactions
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DOI：
10.1016/s0076-6879(06)16002-4
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发表时间：
2006-01-01
期刊：
影响因子：
--
通讯作者：
Peters, Thomas
中科院分区：
文献类型：
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作者：
Angulo, Jesus;Rademacher, Christoph;Peters, Thomas
碳水化合物-蛋白质相互作用的特征通常是解离常数在μ W至mM范围内。这通常与相应复合物的快速解离速率相关，进而导致核磁共振（NMR）化学位移时间尺度和NMR弛豫时间尺度上的快速交换。因此，利用快速交换的核磁共振实验非常适合研究碳水化合物-蛋白质相互作用。一般来说，可以通过观察蛋白质信号或配体共振来分析配体结合。因为大多数与碳水化合物结合的受体蛋白相当大，分子量明显超过30 kDa，因此相应蛋白质谱的分析并不简单，迄今为止只有很少的研究解决了这个问题。因此，我们专注于NMR实验，采用观察游离配体，即碳水化合物信号来分析结合态。两种类型的NMR实验在原子分辨率下分析碳水化合物-蛋白质相互作用方面具有极其重要的价值。而转移核Overhauser效应（NOE）实验提供碳水化合物结合蛋白质的生物活性构象，饱和转移差（STD）NMR光谱提供结合表位和有价值的信息结合热力学和动力学。我们展示了结合转移NOE/STD NMR方法的碳水化合物-蛋白质复合物的分析，使用选定的例子的权力。
Carbohydrate-protein interactions are frequently characterized by dissociation constants in the mu W to mM range. This is normally associated with fast dissociation rates of the corresponding complexes, in turn leading to fast exchange on the nuclear magnetic resonance (NMR) chemical shift time scale and on the NMR relaxation time scale. Therefore, NMR experiments that take advantage of fast exchange are well suited to study carbohydrate-protein interactions. In general, it is possible to analyze ligand binding by observing either protein signals or ligand resonances. Because most receptor proteins to which carbohydrates bind are rather large with molecular weights significantly exceeding 30 kDa, the analysis of the corresponding protein spectra is not trivial, and only very few studies have been addressing this issue so far. We, therefore, focus on NMR experiments that employ observation of free ligand, that is, carbohydrate signals to analyze the bound state. Two types of NMR experiments have been extremely valuable to analyze carbohydrate-protein interactions at atomic resolution. Whereas transferred nuclear Overhauser effect (NOE) experiments deliver bioactive conformations of carbohydrates binding to proteins, saturation transfer difference (STD) NMR spectra provide binding epitopes and valuable information about the binding thermodynamics and kinetics. We demonstrate the power of a combined transfer NOE/STD NMR approach for the analysis of carbohydrate-protein complexes using selected examples.