Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, ON, K1A 0R6, Canada.
Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, ON, K1A 0R6, Canada.
Carbohydr Res. 2022 Dec;522:108704. doi: 10.1016/j.carres.2022.108704. Epub 2022 Oct 20.
Fusobacterium nucleatum is an anaerobic bacterium found in the human mouth where it causes periodontitis. It was also found in colorectal cancer tissues and is linked with pregnancy complications, including pre-term and stillbirths. Cell surface structures of the bacterium could be implicated in pathogenesis. Here we report the structure of the lipopolysaccharide O-chain (OPS) of three strains of F. nucleatum HM-994, HM-995, and HM-997, isolated from cancerous tissues: -3-β-D-ManNAc4Lac-4-β-D-Glc6OAc-3-β-D-FucNAc4N- HM-994. -4-α-L-GalNHBuA-3-α-D-QuiNAc4NHBu-3-α-L-Rha-6-α-D-GalN- HM-995. -3-[α-L-GulNAcA-4-]-β-D-Glc-4-β-D-ManNAcAN-3-β-D-FucNAc4N-3- HM-997. where HBu is 3-hydroxybutyryl, ManNAc4Lac is 4-O-(1-carboxyethyl)-2-acetamido-2-deoxy-mannose. All monosaccharides are in the pyranose form. The structures were determined using standard NMR (2D homo- and hetero-nuclear techniques), MS and chemical methods following gtypical LPS isolation and purification methods. In some cases polymeric material was further degraded in order to produce compounds that gave improved NMR spectra that were easier to be fully interpreted. Structure of the OPS from strain HM-994 was identical to the OPS from F. nucleatum strain MJR 7757 B. Structures of the OPS from HM-995 and HM-997 are novel and to our knowledge have not been previously reported and include the often observed 6-deoxy- sugars found in several F. nucleatum strains and butyrate rather than acetate modifications in the HM-995 strain. This structural knowledge adds to the ever increasing variation found in LPS O-antigen structures from F. nucleatum strain from both oral and cancerous origin and suggests that there may be a multitude of different LPS O-antigen structures elaborated by this organism that may present challenges to any serotyping efforts.
具核梭杆菌是一种存在于人类口腔中的厌氧细菌，可引起牙周炎。它也存在于结直肠癌组织中，并与包括早产和死产在内的妊娠并发症有关。该细菌的细胞表面结构可能与发病机制有关。在这里，我们报告了从癌症组织中分离出的三种具核梭杆菌 HM-994、HM-995 和 HM-997 的脂多糖 O-链（OPS）的结构：-3-β-D-ManNAc4Lac-4-β-D-Glc6OAc-3-β-D-FucNAc4N- HM-994。-4-α-L-GalNHBuA-3-α-D-QuiNAc4NHBu-3-α-L-Rha-6-α-D-GalN- HM-995。-3-[α-L-GulNAcA-4-]-β-D-Glc-4-β-D-ManNAcAN-3-β-D-FucNAc4N-3- HM-997。其中 HBu 是 3-羟基丁酸，ManNAc4Lac 是 4-O-(1-羧乙基)-2-乙酰氨基-2-脱氧-甘露糖。所有单糖均为吡喃糖形式。使用标准 NMR（2D 同核和异核技术）、MS 和化学方法确定结构，同时遵循典型的 LPS 分离和纯化方法。在某些情况下，进一步降解聚合材料以产生化合物，从而产生更容易全面解释的改进 NMR 谱。HM-994 菌株 OPS 的结构与具核梭杆菌 MJR 7757 B 菌株的 OPS 相同。HM-995 和 HM-997 菌株 OPS 的结构是新颖的，据我们所知，以前没有报道过，并且包括在几种具核梭杆菌菌株中经常观察到的 6-去氧糖，以及在 HM-995 菌株中存在丁酸而不是乙酸修饰。这种结构知识增加了来自口腔和癌症来源的具核梭杆菌菌株的 LPS O-抗原结构不断增加的变化，并表明该生物体可能具有多种不同的 LPS O-抗原结构，这可能对任何血清分型工作构成挑战。
