Melaugh W, Phillips N J, Campagnari A A, Karalus R, Gibson B W
Department of Pharmaceutical Chemistry, University of California, San Francisco 94143-0446.
J Biol Chem. 1992 Jul 5;267(19):13434-9.
The first preliminary structure of a surface lipooligosaccharide from Haemophilus ducreyi has been determined. The major oligosaccharide was released by mild acid hydrolysis and analyzed by liquid secondary ion and tandem mass spectrometry. The mass spectral data combined with composition and methylation analysis yielded the most probable structure; Gal1----4GlcNAc1----3Gal1----4Hep1----6Glc1----( Hep1----2Hep1----)3,4Hep1---- KDO, where the reducing terminal 3-deoxy-D-manno-octulosonic acid (or KDO) exists in an anhydro form. This anhydro species results from the elimination of a phosphate from C-4 of KDO during mild acid hydrolysis. The core heptose trisaccharide consists of L-glycero-D-manno-heptose, but analysis of the peracetylated sugars indicated that the 1,4-linked heptose is likely D-glycero-D-manno-heptose. The monoclonal antibody 3F11 generated against Neisseria gonorrhoeae also binds to this lipooligosaccharide and suggests that the terminal trisaccharide is Gal beta 1----4GlcNAc beta 1----3Gal beta 1----, an epitope found in the glycose moiety of the human erythrocyte glycosphingolipid lactoneotetraglycosylceramide. Mass spectrometric and composition analysis of the lipid A moiety shows that it is similar to the lipid A of Haemophilus influenzae strain I-69 Rd-/b+ proposed by Helander et al. (Helander, I. M., Lindner, B., Brade, H., Altmann, K., Lindberg, A. A., Rietschel, E. T., and Zähringer, U. (1988) Eur. J. Biochem. 177, 483-492). Electrospray mass spectrometric analysis of the intact O-deacylated lipooligosaccharides gave an average Mr of 2710, and supported an overall structure consisting of the above nonasaccharide linked directly to a diphosphorylated lipid A moiety through the single KDO which is phosphorylated. This structure should provide a framework to investigate the roles of lipooligosaccharides in the host immunochemical response and pathology of H. ducreyi infection, a leading cause of genital ulcer disease.
已确定来自杜克雷嗜血杆菌的表面脂寡糖的首个初步结构。主要的寡糖通过温和酸水解释放，并通过液体二次离子和串联质谱进行分析。质谱数据结合组成和甲基化分析得出了最可能的结构：Gal1----4GlcNAc1----3Gal1----4Hep1----6Glc1----(Hep1----2Hep1----)3,4Hep1----KDO，其中还原端的3-脱氧-D-甘露-辛酮糖酸（或KDO）以脱水形式存在。这种脱水形式是在温和酸水解过程中KDO的C-4位的磷酸被消除导致的。核心庚糖三糖由L-甘油-D-甘露-庚糖组成，但对全乙酰化糖的分析表明，1,4-连接的庚糖可能是D-甘油-D-甘露-庚糖。针对淋病奈瑟菌产生的单克隆抗体3F11也与这种脂寡糖结合，表明末端三糖是Galβ1----4GlcNAcβ1----3Galβ1----，这是在人红细胞糖鞘脂乳糖新四糖神经酰胺的糖部分中发现的一个表位。脂多糖A部分的质谱和组成分析表明，它与Helander等人提出的流感嗜血杆菌I-69 Rd-/b+菌株的脂多糖A相似（Helander, I. M., Lindner, B., Brade, H., Altmann, K., Lindberg, A. A., Rietschel, E. T., and Zähringer, U. (1988) Eur. J. Biochem. 177, 483 - 492）。对完整的O-脱酰基脂寡糖进行电喷雾质谱分析得到平均分子量为2710，并支持由上述九糖通过单个磷酸化的KDO直接连接到二磷酸化的脂多糖A部分组成的整体结构。这个结构应该为研究脂寡糖在宿主免疫化学反应以及杜克雷嗜血杆菌感染（生殖器溃疡疾病的主要病因）的病理学中的作用提供一个框架。
