Yeh H Y, Jacobs D M
Department of Microbiology, School of Medicine and Biomedical Sciences, State University of New York, Buffalo 14214.
J Bacteriol. 1992 Jan;174(1):336-41. doi: 10.1128/jb.174.1.336-341.1992.
The role of the length of the O-antigen polysaccharide side chain of bacterial lipopolysaccharide (LPS) in biological and model membrane systems was investigated. LPS from Salmonella typhimurium ATCC 14028 was chromatographed on a Sephadex G-200 column in the presence of sodium deoxycholate and separated into three fractions on the basis of molecular size. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western blot (immunoblot), and chemical analyses indicated that these fractions differed from each other primarily in the number of repeating units in the O-antigen polysaccharide side chain. In a biological system fractions 2 and 3 had the same effects to induce mitogenesis in murine lymphocytes, but fraction 1 was less effective than the other two fractions. In a model membrane system, LPS induced changes in small unilamellar vesicles (SUVs) which were measured by changes in the behavior of a fluorescent probe, 1,6-diphenylhexa-1,3,5-triene (DPH), and interaction of increasing amounts of all LPS fractions with SUVs gradually increased DPH anisotropy. Fractions 2 and 3 had similar effects on the SUVs as detected by changes in DPH anisotropy, while fraction 1 had almost twice as much activity as the other two fractions. These results suggest that the polysaccharide side chain of LPS may modulate the ability of biologically active lipid A to interact with cells and model membranes. In addition, factors other than changes in membrane fluidity may play a role in mediating LPS-induced cell activation.
研究了细菌脂多糖（LPS）的O抗原多糖侧链长度在生物膜和模型膜系统中的作用。鼠伤寒沙门氏菌ATCC 14028的LPS在脱氧胆酸钠存在下于Sephadex G - 200柱上进行色谱分析，并根据分子大小分离成三个组分。十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳、蛋白质免疫印迹（免疫印迹）和化学分析表明，这些组分彼此之间的主要差异在于O抗原多糖侧链中重复单元的数量。在生物系统中，组分2和3在诱导小鼠淋巴细胞有丝分裂方面具有相同的作用，但组分1的效果不如其他两个组分。在模型膜系统中，LPS诱导小单层囊泡（SUVs）发生变化，通过荧光探针1,6 - 二苯基己三烯（DPH）行为的变化来测量，并且所有LPS组分与SUVs相互作用量的增加逐渐增加了DPH各向异性。通过DPH各向异性的变化检测到，组分2和3对SUVs具有相似的作用，而组分1的活性几乎是其他两个组分的两倍。这些结果表明，LPS的多糖侧链可能调节生物活性脂质A与细胞和模型膜相互作用的能力。此外，膜流动性变化以外的因素可能在介导LPS诱导的细胞活化中起作用。
