MacLean Leann L, Webb Ann C, Perry Malcolm B
Institute for Biological Sciences, National Research Council, Ottawa, Canada K1A OR6.
Carbohydr Res. 2006 Nov 6;341(15):2543-9. doi: 10.1016/j.carres.2006.08.008. Epub 2006 Sep 1.
The structure of the antigenic O-polysaccharide (O-PS) of the lipopolysaccharide (LPS) produced by the enterohemorrhagic strain of Escherichia coli O48:H21 (EHEC) has been elucidated. The O-PS obtained by mild acid hydrolysis of the LPS had [alpha]D +95 (water) and was composed of L-rhamnose (L-Rha), D-galactose (D-Gal), 2-amino-2-deoxy-D-glucose (D-GlcN), 2-amino-2-deoxy-D-galactose (D-GalN), and D-galacturonic acid (D-GalA) (1:1:1:1:1). From the results of methylation analysis, mass spectrometry, 2D NMR, and DOC-PAGE, the O-PS was shown to be a high molecular mass polymer of a repeating pentasaccharide unit having the structure: [structure: see text]. The D-Gal pA non-reducing end groups in the O-PS were partially O-acetylated (approximately 30%) at the O-2 and O-3 positions and the degree of acetylation was variable from batch to batch cell production.
肠出血性大肠杆菌O48:H21（EHEC）产生的脂多糖（LPS）的抗原性O-多糖（O-PS）结构已被阐明。通过对LPS进行温和酸水解得到的O-PS的比旋光度[α]D为+95（水），由L-鼠李糖（L-Rha）、D-半乳糖（D-Gal）、2-氨基-2-脱氧-D-葡萄糖（D-GlcN）、2-氨基-2-脱氧-D-半乳糖（D-GalN）和D-半乳糖醛酸（D-GalA）组成（1:1:1:1:1）。甲基化分析、质谱、二维核磁共振和十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（DOC-PAGE）结果表明，O-PS是一种具有以下结构的重复五糖单元的高分子量聚合物：[结构：见原文]。O-PS中的D-Gal pA非还原端基在O-2和O-3位部分O-乙酰化（约30%），乙酰化程度因批次不同而有所变化。
