Saturation-transfer difference (STD)-NMR spectroscopy has been widely used to screen potential ligands for binding to large receptor molecules. The STD-NMR experiment is typically based on a proton NMR spectrum, which can suffer from spectral overlap, leading to missing information in STD-based epitope mapping. Two-dimensional STD-NMR experiments can alleviate spectral overlap, but are time consuming. Here, we examine the feasibility of saturating protons in a receptor molecule and observing the STD effect on nearby carbon nuclei after transferring polarization from protons to carbons using the insensitive nuclei enhanced by polarization transfer (INEPT) pulse sequence. We show that under favorable conditions, a 1H→13C STD-INEPT experiment can give information similar to that obtained from a two-dimensional heteronuclear experiment, but in significantly less time. The STD-INEPT experiment could be especially useful when studying mixtures of ligands in which the peak positions in the proton and HSQC spectrum change significantly, and in particular, when using high-throughput, automated methods to analyze the data.

中文翻译：

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使用 INEPT 偏振转移的 13C 饱和转移差 (STD)-NMR 实验

饱和转移差 (STD)-NMR 光谱已被广泛用于筛选与大受体分子结合的潜在配体。STD-NMR 实验通常基于质子 NMR 光谱，它可能会受到光谱重叠的影响，导致基于 STD 的表位映射中的信息丢失。二维 STD-NMR 实验可以减少光谱重叠，但很耗时。在这里，我们研究了使受体分子中的质子饱和的可行性，并在使用极化转移 (INEPT) 脉冲序列增强的不敏感核将极化从质子转移到碳后观察 STD 对附近碳核的影响。我们表明，在有利条件下，1H→13C STD-INEPT 实验可以提供类似于从二维异核实验中获得的信息，但时间要短得多。STD-INEPT 实验在研究质子和 HSQC 谱中峰值位置发生显着变化的配体混合物时特别有用，尤其是在使用高通量、自动化方法分析数据时。