Kremp A, Schliephacke M, Kull U, Schmid H P
Exp Cell Res. 1986 Oct;166(2):553-7. doi: 10.1016/0014-4827(86)90500-8.
A 19S particle was purified from tobacco (Nicotiana rustica) leaf cells. Its density was determined as 1296 g/cm3 in Cs2SO4-DMSO gradients, indicating the presence of RNA and protein. Polyacrylamide gel electrophoresis (PAGE) revealed eight distinct proteins in the range of 20-30 kD and RNA in the range of 70-80 nucleotides. Electron microscopic examination showed the same raspberry-shaped structure with a central depression as described for prosomes. We conclude that tobacco 19S particles represent small cytoplasmic complexes, possessing biochemical and structural characteristics similar to the hither-to known prosomes of animal cells.
从烟草（黄花烟草）叶细胞中纯化出一种19S颗粒。在硫酸铯-二甲基亚砜梯度中测定其密度为1.296 g/cm³，表明存在RNA和蛋白质。聚丙烯酰胺凝胶电泳（PAGE）显示在20 - 30 kD范围内有8种不同的蛋白质，以及在70 - 80个核苷酸范围内的RNA。电子显微镜检查显示其具有与前体微粒所描述的相同的带有中心凹陷的悬钩子形状结构。我们得出结论，烟草19S颗粒代表小型细胞质复合物，具有与迄今已知的动物细胞前体微粒相似的生化和结构特征。
