Jantzen H
Eur J Biochem. 1981 Oct;119(2):347-52. doi: 10.1111/j.1432-1033.1981.tb05614.x.
Ribosomes and subunits from Acanthamoeba castellanii were purified. The pattern of ribosomal proteins was analysed by two-dimensional gel electrophoresis. The small subunit of cytoplasmic ribosomes contains 25 and the large 40 proteins. After incubation of exponentially growing cells with ortho[33P]phosphate for 1 h, one basic protein of the small subunit was radiolabelled. This phosphorylated protein has a molecular weight of about 45000 as estimated by dodecylsulfate/polyacrylamide gel electrophoresis. The level of phosphorylated ribosomal protein as estimated by staining of proteins separated by two-dimensional gel electrophoresis changes in response to growth conditions. The maximum level occurs after adding fresh nutrient medium to cells which have been allowed to grow to high density, whereas ribosomes of exponentially growing cells contain low amounts. Transfer of exponentially growing cells into a non-nutrient medium induces the formation of cysts containing ribosomes almost devoid of phosphorylated protein.
对卡氏棘阿米巴的核糖体和亚基进行了纯化。通过二维凝胶电泳分析核糖体蛋白的模式。细胞质核糖体的小亚基含有25种蛋白，大亚基含有40种蛋白。将指数生长期的细胞与正[33P]磷酸盐孵育1小时后，小亚基的一种碱性蛋白被放射性标记。通过十二烷基硫酸钠/聚丙烯酰胺凝胶电泳估计，这种磷酸化蛋白的分子量约为45000。通过对二维凝胶电泳分离的蛋白进行染色估计，磷酸化核糖体蛋白的水平会根据生长条件而变化。在向已生长至高密度的细胞中添加新鲜营养培养基后，其水平达到最高，而指数生长期细胞的核糖体中含量较低。将指数生长期的细胞转移到无营养培养基中会诱导形成含有几乎不含磷酸化蛋白的核糖体的囊肿。
