Centre for Plant Molecular Biology, Department of Biology, McGill University, 1205 Docteur Penfield Avenue, Montreal H3A 1B1, Canada.
EMBO J. 1985 Dec 1;4(12):3041-6. doi: 10.1002/j.1460-2075.1985.tb04043.x.
Rhizobium bacteroids in nodule cells are surrounded by the peribacteroid membrane (pbm), which is derived from the host plasma membrane during infection. The pbm was purified from R. japonicum 61A76-induced soybean nodules and analyzed by comparing it with the host cell plasma membrane for the presence of nodulins, nodule-specific plant proteins. Nodulins were found in pbm by reacting Western blots with a nodule-specific antiserum raised against the pbm. Peribacteroid fluid (the fluid enclosed in the pbm) was also found to contain several nodulins. The pbm nodulins were confirmed to be of plant origin by in vitro translation of poly(A) nodule mRNA followed by immunoprecipitation by the nodule-specific antiserum. Antibodies raised against a synthetic peptide corresponding to a repeated domain in nodulin-24, a pbm nodulin, and the nodule-specific pbm antiserum reacted exclusively with the pbm. The absence of pbm-nodulins in the plasma membrane suggests that the infected cells direct the intracellular transport of the pbm nodulins exclusively to this de novo synthesized subcellular compartment essential for symbiotic nitrogen fixation.
根瘤菌类菌体被类菌体周膜（pbm）所包围，该膜在侵染过程中来源于宿主质膜。从 Rhizobium japonicum 61A76 诱导的大豆根瘤中纯化 pbm，并通过与宿主细胞质膜进行比较，分析 pbm 是否存在结瘤素，即植物特有的结瘤蛋白。通过与针对 pbm 产生的结瘤素特异性抗血清进行 Western blot 反应，发现 pbm 中存在结瘤素。类菌体周质液（pbm 包裹的液体）中也发现含有几种结瘤素。通过对多聚 A 结瘤 mRNA 进行体外翻译，然后用结瘤素特异性抗血清进行免疫沉淀，证实 pbm 结瘤素来源于植物。针对结瘤素-24 中重复结构域的合成肽产生的抗体、pbm 结瘤素和结瘤素特异性 pbm 抗血清仅与 pbm 发生反应。质膜中不存在 pbm 结瘤素，这表明感染细胞将 pbm 结瘤素的细胞内运输专门导向这一新合成的、对共生固氮至关重要的亚细胞隔室。
