Structural analysis of the capsular polysaccharide from Campylobacter jejuni RM1221
Structural analysis of the capsular polysaccharide from Campylobacter jejuni RM1221
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DOI：
10.1002/cbic.200600508
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发表时间：
2007-04-16
期刊：
影响因子：
3.2
通讯作者：
Vinogradov, Evgeny
中科院分区：
文献类型：
--
作者：
Gilbert, Michel;Mandrell, Robert E.;Vinogradov, Evgeny
空肠弯曲菌RM 1221株（Penner血清型HS：53）的全基因组是最近报道的，它含有一个新的荚膜多糖（CPS）生物合成位点。已知细胞表面碳水化合物如CPS对于细菌存活是重要的，并且通常有助于致病。在这项研究中，我们描述了C的CPS的完整结构。jejuni RM 1221的氨基酸序列，通过核磁共振、质谱和化学方法进行了鉴定。CPS含有6-脱氧-D-甘露-庚糖和D-苏-甘露-2-酮糖（D-木糖），这两种单糖很少在细菌多糖中发现。CPS具有三糖重复单元的线性主链的规则结构，由两个α-和一个β-6-脱氧-D-甘露-吡喃庚糖残基组成，其通过磷酸二酯键连接。木酮糖的分支残基以非化学计量方式并入：主链的每个三糖重复单元不带有、带有一个或两个木酮糖残基。木酮糖糖苷键是极其酸不稳定的，并且不清楚它们如何在胃肠道的酸性条件下保存，弯曲杆菌在感染期间驻留在胃肠道中。我们还发现，C. jejuni RM 1221在其它C. Penner血清型HS：53的空肠菌株，包括血清型HS：53参考菌株RM 43435。
The complete genome of Campylobacter jejuni strain RM1221 (Penner serotype HS:53) was reported recently and contains a novel capsular polysaccharide (CPS) biosynthesis locus. Cell-surface carbohydrates such as CPS are known to be important for bacterial survival and often contribute to pathogenesis. In this study, we describe the complete structure of the CPS of C. jejuni RM1221, which was determined by using NMR spectroscopy, MS, and chemical methods. The CPS contains 6-Deoxy-D-manno-heptose and D-threo-pent-2-ulose (D-xyulose), two monosaccharides that are rarely found in bacterial polysaccharides. The CPS has a regular structure of a linear main chain of trisaccharide repeating units, composed of two alpha- and one beta-6-deoxy-D-manno-heptopyranose residues, which are linked through a phosphodiester linkage. Branching residues of xylulose are incorporated nonstoichiometrically: each trisaccharide repeating unit of the main chain bears no, one, or two xylulose residues. The xylulose glycosidic linkages are extremely acid labile, and it is not clear how they can be preserved under the acidic conditions of the gastrointestinal tract, where Campylobacter resides during infection. We have also shown that the CPS biosynthesis genes of C. jejuni RM1221 are conserved in other C. jejuni strains of the Penner serotype HS;53, including serotype HS:53 reference strain RM43435.