Erbel Paul J A, Seidel Ronald, Macintosh Scott E, Gentile Lisa N, Amor Juan C, Kahn Richard A, Prestegard James H, McIntosh Lawrence P, Gardner Kevin H
Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas TX 75390-9038, USA.
J Biomol NMR. 2004 Jun;29(2):199-204. doi: 10.1023/B:JNMR.0000019252.65073.24.
We have previously reported the identification of the cyclic enterobacterial common antigen (ECA(CYC)) polysaccharide in E. coli strains commonly used for heterologous protein expression (PJA Erbel et al., J. Bacteriol. 185 (2003): 1995). Following this initial report, interactions among several NMR groups established that characteristic N -acetyl signals of ECA(CYC) have been observed in (15)N-(1)H HSQC spectra of samples of various bacterially-expressed proteins suggesting that this water-soluble carbohydrate is a common contaminant. We provide NMR spectroscopic tools to recognize ECA(CYC) in protein samples, as well as several methods to remove this contaminant. Early recognition of ECA-based NMR signals will prevent time-consuming analyses of this copurifying carbohydrate.
我们之前曾报道过，在常用于异源蛋白表达的大肠杆菌菌株中鉴定出了环状肠杆菌共同抗原（ECA(CYC)）多糖（PJA·埃贝尔等人，《细菌学杂志》185卷（2003年）：1995页）。在这一初步报告之后，几个核磁共振研究小组之间的相互作用证实，在各种细菌表达蛋白样品的（15）N-（1）H HSQC谱图中观察到了ECA(CYC)的特征性N-乙酰信号，这表明这种水溶性碳水化合物是一种常见污染物。我们提供了核磁共振光谱工具来识别蛋白质样品中的ECA(CYC)，以及几种去除这种污染物的方法。基于ECA的核磁共振信号的早期识别将避免对这种共纯化碳水化合物进行耗时的分析。
