Schliephacke M, Kremp A, Schmid H P, Köhler K, Kull U
Biologisches Institut der Universität, Stuttgart/Bundesrepublik Deutschland.
Eur J Cell Biol. 1991 Jun;55(1):114-21.
From different plant tissues such as tobacco (Nicotiana rustica), potato (Solanum tuberosum), and mung bean (Phaseolus radiatus), ring- or cylinder-shaped particles called prosomes were isolated by either sucrose gradient centrifugation or fast protein liquid chromatography (FPLC). These particles have a diameter of 12 to 14 nm and a length of 16 to 18 nm. They migrate under conditions of nondenaturing gel electrophoresis as one distinct band. Sedimentation coefficient and buoyant density in Cs2SO4 of the plant prosomes were determined by analytical ultracentrifugation to be approximately 23S and 1.23 g/cm3, respectively. The total molecular mass was estimated by gel filtration to be 650 kDa. Plant prosomes are composed of 12 to 15 proteins with molecular masses in the range of 24 to 35 kDa with isoelectric points of pH 5 to 7 as revealed by two-dimensional gel electrophoresis. The protein patterns of prosomes from the three different plant species are very similar. Polyclonal antisera against potato prosomes reacted in Western blots with prosomal proteins of all three plant species. They also bind to some prosomal proteins of animal species. Antisera against animal prosomes react with some proteins of plant prosomes. As shown by lectin blotting, plant prosomes are glycosylated carrying glucosyl- or mannosyl, and N-acetylgalactosaminyl residues. Prosomal preparations contain non-stoichiometric amounts of small RNA of about 80 kDa. These results suggest that plant prosomes are structurally and functionally homologous to prosomes of other eukaryotic cells.
从烟草（黄花烟草）、马铃薯（马铃薯）和绿豆（绿豆）等不同植物组织中，通过蔗糖梯度离心或快速蛋白质液相色谱（FPLC）分离出称为前体小体的环形或圆柱形颗粒。这些颗粒直径为12至14纳米，长度为16至18纳米。它们在非变性凝胶电泳条件下迁移为一条明显的条带。通过分析超速离心法测定植物前体小体在Cs2SO4中的沉降系数和浮力密度分别约为23S和1.23 g/cm3。通过凝胶过滤估计总分子量为650 kDa。二维凝胶电泳显示，植物前体小体由12至15种蛋白质组成，分子量在24至35 kDa范围内，等电点为pH 5至7。来自三种不同植物物种的前体小体的蛋白质模式非常相似。抗马铃薯前体小体的多克隆抗血清在蛋白质印迹中与所有三种植物物种的前体小体蛋白发生反应。它们还与动物物种的一些前体小体蛋白结合。抗动物前体小体的抗血清与植物前体小体的一些蛋白质发生反应。如凝集素印迹所示，植物前体小体被糖基化，带有葡萄糖基或甘露糖基以及N-乙酰半乳糖胺残基。前体小体制剂含有非化学计量的约80 kDa的小RNA。这些结果表明，植物前体小体在结构和功能上与其他真核细胞的前体小体同源。
