STRUCTURE/FUNCTION RELATIONSHIP OF LIPID A IN CAMPYLOBACTER RECTUS

直弯杆菌脂质A的结构与功能关系 弯曲杆菌是一种革兰氏阴性、厌氧、氧化酶阳性， 一种能动的杆状细菌 慢性成人牙周炎和牙周病的病原体 免疫抑制的患者如患有糖尿病的患者， 艾滋病和克罗恩病。 脂多糖（LPS），一种细胞壁成分 是革兰氏阴性菌的毒力因子 与牙周病相关，因为它能够穿透牙龈 上皮组织和刺激骨吸收活性。 而且 已经确定LPS的内毒素性质是由 它们的脂质A成分。 化学和生物学表征研究 已经表明，脂质A，在干重的37.2%，是最单一的 C.直肌 我们假设脂质A和 其相关的核心寡糖可能在引发 在感染C.直肌 是 本项目的目的是确定C中脂质A的结构。 直肌，以便深入了解其化学成分之间的关系， 结构和生物学功能。 为了实现这一目标， C.直肌在支原体-甲酸盐-富马酸盐肉汤中生长， 使用冷MgCl2-乙醇沉淀分离。 从1.85 g细胞 (dry重），回收160.7mg LPS;产率为8.7%。 ThePresence 用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳法证实了LPS的存在 电泳（SDS-PAGE）。 C.直肌LPS带型，典型的 那些由吉莱斯皮等人建立的。（I & I，1988），当 凝胶用考马斯蓝和银染色。 的考马斯 使用牛血清白蛋白（BSA）标准品的蓝色蛋白测定显示， LPS样品中的显著蛋白质，而UV光谱法在A260 - 280 确定无核酸污染。 在布莱-戴尔的提取之后 用氯仿：甲醇（2：1）溶液，薄层层析 显示LPS样品不含磷脂。 2-酮基-3-脱氧辛酸酯（KDO），a 通过比色测定在A548处定量LPS特有的糖， 发现以LPS干重的0.45%存在。 在随后 程序中，将通过用1%（volvol）水解LPS提取脂质A 乙酸和由13C-和31P-NMR引起的结构。 结构 C.本研究的直肌将提供 深入了解结构和内毒素功能之间的关系。 结果也将有分类相关性，以建立如果该物种 显示与所述脂质A结构的独特特征同源 空肠弯曲菌

Structure-Function Relationship of Lipid A in Campylobacter Rectus Campylobacter rectus is a grarn-negative, anaerobic, oxidase-positive, motile rod-shaped bacterium which has been implicated as a potential pathogen of chronic adult periodontitis and periodontal disease of immunosuppressed patients such as those suffering from diabetes mellitus, AIDS, and Crohn's disease. Lipopolysaccharide (LPS), a cell wall component of gram-negative bacteria, is a virulence factor in those bacteria associated with periodontal disease as it is able to penetrate gingival epithelial tissue and stimulate bone resorptive activity. Furthermore, it has been established that the endotoxic properties of LPS are mediated by their lipid A component. Chemical and biological characterization studies have shown that lipid A, at 37.2% of the dry weight, is the single most abundant component of LPS in C. rectus. We hypothesize that the lipid A and its associated core oligosaccharide may be important in the elicitation of prostoglandins observed in the host upon infection with C. rectus. It is the intent of this project to determine the structure of the lipid A in C. rectus in order to provide insight into relationships between its chemical structure and biological functions. To achieve this goal, batch cultures of C. rectus were grown in mycoplasma-formate-fumarate broth, and the LPS isolated using a cold MgC12-ethanol precipitation. From 1.85 g of cells (dry weight), 160.7 mg of LPS was recovered; a yield of 8.7%. Thepresence of LPS was verified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). C. rectus LPS banding patterns, typical of those established by Gillespie, et. al. (I & I, 1988), were observed when the gels were stained with Coomassie blue and silver stain. A Coomassie blue protein assay using bovine serum albumin (BSA) standards revealed no significant protein within the LPS sample, while UV spectrometry at A260-280 determined no nucleic acid contamination. Following a Bligh-Dyer extraction using a solution of chloroform: methanol (2:1), thin layer chromatography revealed LPS sample free of phospholipids. 2-keto-3-deoxyoctonate (KDO), a sugar unique to LPS, was quantified by a colorimetric assay at A548, and found to be present at 0.45% of the dr weight of LPS. In subsequent procedures, lipid A will be extracted by hydrolysis of LPS with 1% (volvol) acetic acid and the structure elicited by 13C- and 31P-NMR. The structure of the lipid A component of C. rectus resulting from this study will provide insight into relationships between the structure and endotoxic functions. Results will also have taxonomic relevance to establish if this species shows homology with the unique features of the lipid A structure described in Campylobacter jejuni.