Stein M A, McAllister S A, Torian B E, Diedrich D L
Department of Microbiology, Immunology, and Parasitology, Louisiana State University Medical Center, New Orleans 70112-1393.
J Bacteriol. 1992 May;174(9):2858-64. doi: 10.1128/jb.174.9.2858-2864.1992.
The ability of Bdellovibrio bacteriovorus to relocalize the OmpF major outer membrane porins from its Escherichia coli prey to its own outer membranes is diminished in prey expressing smooth lipopolysaccharide (S-LPS). Since porins exist in the membrane complexed with LPS, we examined the LPS associated with relocalized porin to determine whether it had been acquired intact, mixed or replaced with Bdellovibrio LPS, or derivatized by the bdellovibrios. The relocalized trimers were found associated with the same LPS originally bound to them in the E. coli. The bulk-phase LPS from bdellovibrios grown on various chemotypes of rough prey was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to determine whether more than the trimer-bound LPS was acquired by the bdellovibrios. This analysis revealed bands of Bdellovibrio LPS matching the LPS chemotype of the prey. One or two other bands were identical in migration to the LPS of prey-independent mutants of B. bacteriovorus and represented bdellovibrio-synthesized LPS. The LPS of bdellovibrios grown on prey with radiolabeled lipid A showed radioactivity only in gel band positions identical with those of the prey's LPS. The amount of this prey-derived LPS was shown by enzyme-linked immunosorbent assay to reach a constant value during the purification of the bdellovibrios, and it represented approximately 25% of the total Bdellovibrio LPS. Immunoelectron microscopy confirmed the presence of prey-derived LPS on the cell surface of bdellovibrios, and no evidence could be found for bdellovibrio-induced modifications of the relocalized prey LPS.
在表达光滑脂多糖（S-LPS）的猎物中，食菌蛭弧菌将大肠杆菌猎物的外膜孔蛋白OmpF重新定位到自身外膜的能力会减弱。由于孔蛋白存在于与LPS复合的膜中，我们检查了与重新定位的孔蛋白相关的LPS，以确定它是完整获取的、混合的、被蛭弧菌LPS取代的，还是被蛭弧菌衍生化的。发现重新定位的三聚体与最初在大肠杆菌中与其结合的相同LPS相关。通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分析了在各种粗糙猎物化学类型上生长的蛭弧菌的本体相LPS，以确定蛭弧菌是否获取了超过三聚体结合LPS的量。该分析揭示了与猎物LPS化学类型匹配的蛭弧菌LPS条带。另外一两条带在迁移上与食菌蛭弧菌猎物非依赖性突变体的LPS相同，代表蛭弧菌合成的LPS。在含有放射性标记脂质A的猎物上生长的蛭弧菌的LPS仅在与猎物LPS相同的凝胶带位置显示放射性。通过酶联免疫吸附测定表明，这种源自猎物的LPS的量在蛭弧菌纯化过程中达到恒定值，并且它约占蛭弧菌总LPS的25%。免疫电子显微镜证实了在蛭弧菌细胞表面存在源自猎物的LPS，并且没有发现蛭弧菌对重新定位的猎物LPS进行修饰的证据。
