Lukasiewicz Jolanta, Niedziela Tomasz, Jachymek Wojciech, Kenne Lennart, Lugowski Czeslaw
Department of Immunochemistry, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, R. Weigla 12, 53-114 Wroclaw, Poland.
Glycobiology. 2006 Jun;16(6):538-50. doi: 10.1093/glycob/cwj094. Epub 2006 Feb 20.
Plesiomonas shigelloides is a Gram-negative rod associated with episodes of intestinal infections and outbreaks of diarrhea in humans. The extraintestinal infections caused by this bacterium, for example, endopthalmitis, meningitidis, bacteremia, and septicemia, usually have gastrointestinal origin and serious course. The lipopolysaccharide (LPS, endotoxin) as virulence factor is important in enteropathogenicity of this bacterium. LPSs of P. shigelloides and especially their lipid A part, that is, the immunomodulatory center of LPS, have not been extensively investigated. The structure of P. shigelloides O54 lipid A was determined by chemical analysis combined with MALDI-TOF mass spectrometry, and the intact Kdo-containing core region was investigated by NMR spectroscopy on deacylated LPS. Products from alkaline deacylation of LPS, containing 4-substituted uronic acids, are usually very complex and difficult to separate. Since Kdo residues, like sialic acids, form complexes with serotonin, we used immobilized serotonin for one-step isolation of oligosaccharide containing the intact Kdo region from the reaction mixture by affinity chromatography. The major form of lipid A was built of beta-d-GlcpN4PPEtn-(1-->6)-alpha-d-GlcpN1P disaccharide substituted with 14:0(3-OH), 12:0(3-OH), 14:0(3-O-14:0), and 12:0(3-O-12:0) acyl groups at N-2, O-3, N-2', and O-3', respectively. This is a novel structure among known lipid A molecules. Analysis of intact Kdo-lipid A region, lipid A and its linkage with the core oligosaccharide completes the structural investigation of P. shigelloides O54 LPS, resolving the entire molecule. Biological activities and observed discrepancy between in vitro and in vivo activity of P. shigelloides and Escherichia coli LPS are discussed.
类志贺邻单胞菌是一种革兰氏阴性杆菌，与人类肠道感染和腹泻暴发有关。这种细菌引起的肠外感染，例如眼内炎、脑膜炎、菌血症和败血症，通常起源于胃肠道且病程严重。脂多糖（LPS，内毒素）作为毒力因子在该细菌的肠道致病性中很重要。类志贺邻单胞菌的脂多糖，尤其是其脂质A部分，即脂多糖的免疫调节中心，尚未得到广泛研究。通过化学分析结合基质辅助激光解吸电离飞行时间质谱（MALDI - TOF MS）确定了类志贺邻单胞菌O54脂质A的结构，并通过对脱酰化脂多糖进行核磁共振光谱研究了完整的含Kdo核心区域。脂多糖碱性脱酰化产物含有4 - 取代糖醛酸，通常非常复杂且难以分离。由于Kdo残基与唾液酸一样能与血清素形成复合物，我们使用固定化血清素通过亲和色谱从反应混合物中一步分离出含有完整Kdo区域的寡糖。脂质A的主要形式由β - d - GlcpN4PPEtn - (1→6) - α - d - GlcpN1P二糖组成，在N - 2、O - 3、N - 2'和O - 3'位置分别被14:0(3 - OH)、12:0(3 - OH)、14:0(3 - O - 14:0)和12:0(3 - O - 12:0)酰基取代。这在已知的脂质A分子中是一种新结构。对完整的Kdo - 脂质A区域、脂质A及其与核心寡糖的连接进行分析，完成了类志贺邻单胞菌O54脂多糖的结构研究，解析了整个分子。讨论了类志贺邻单胞菌和大肠杆菌脂多糖的生物学活性以及观察到的体外和体内活性差异。
