Landersjö C, Weintraub A, Widmalm G
Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, Sweden.
Eur J Biochem. 2001 Apr;268(8):2239-45. doi: 10.1046/j.1432-1327.2001.02095.x.
The structure of the O-antigen polysaccharide from Escherichia coli O172 has been determined. In combination with sugar analysis, NMR spectroscopy shows that the polysaccharide is composed of pentasaccharide repeating units. Sequential information was obtained by mass spectrometry and two-dimensional NMR techniques. An O-acetyl group was present as 0.7 equivalent per repeating unit. Treatment of the O-deacetylated polysaccharide with aqueous 48% hydrofluoric acid rendered cleavage of the phosphodiester in the backbone of the polymer and the pentasaccharide isolated after gel permeation chromatography was structurally characterized. Subsequent NMR experiments on polymeric materials revealed the structure of the repeating unit of the O-polysaccharide from E. coli O172 as:-->P-4)-alpha-D-Glcp-(1-->3)-alpha-L-FucpNAc-(1-->3)-alpha-D- GlcpNAc-(1-->3)-alpha-L-FucpNAc-(1-->4)-alpha-D-Glcp6Ac-(1-->
大肠杆菌O172的O抗原多糖结构已被确定。结合糖分析，核磁共振光谱表明该多糖由五糖重复单元组成。通过质谱和二维核磁共振技术获得了序列信息。每个重复单元中存在0.7当量的O - 乙酰基。用48%的氢氟酸水溶液处理O - 脱乙酰化多糖导致聚合物主链中的磷酸二酯键断裂，凝胶渗透色谱分离后得到的五糖进行了结构表征。随后对聚合材料进行的核磁共振实验揭示了大肠杆菌O172的O - 多糖重复单元的结构为：-->P-4)-α-D-葡萄糖-(1-->3)-α-L-岩藻糖胺-(1-->3)-α-D-葡萄糖胺-(1-->3)-α-L-岩藻糖胺-(1-->4)-α-D-葡萄糖6-乙酸酯-(1-->
