Rodrigues-Pousada C, Hayes D H
Eur J Biochem. 1978 Sep 1;89(2):407-15. doi: 10.1111/j.1432-1033.1978.tb12543.x.
Tetrahymena pyriformis ribosomal subunits were obtained by incubation of post-mitochondrial supernatant in the presence of 0.2 mM GTP and 0.1 mM puromycin for 45 min at 28 degrees C, followed by sucrose density gradient centrifugation. Isolated 40-S subunits were able to reassociate in vitro in the presence of 5 mM MgCl2 and 50 mM KCl and to perform poly(U)-dependent protein synthesis. The 60-S subunit carries the peptidyl transferase activity. The number of proteins in T. pyriformis ribosomal subunits was determined by two-dimensional polyacrylamide gel electrophoresis. The 40-S subunit contains 30 different protein species (including two acidic proteins). The 60-S subunit contains 35 different protein species (including two acidic proteins). The proteins were numbered following the system of Kaltschmidt and Wittmann.
将梨形四膜虫的线粒体后上清液在含有0.2 mM GTP和0.1 mM嘌呤霉素的条件下于28℃孵育45分钟，随后进行蔗糖密度梯度离心，从而获得梨形四膜虫核糖体亚基。分离得到的40-S亚基能够在5 mM MgCl2和50 mM KCl存在的情况下在体外重新缔合，并进行依赖于聚尿苷酸的蛋白质合成。60-S亚基具有肽基转移酶活性。通过二维聚丙烯酰胺凝胶电泳确定梨形四膜虫核糖体亚基中的蛋白质数量。40-S亚基包含30种不同的蛋白质种类（包括两种酸性蛋白质）。60-S亚基包含35种不同的蛋白质种类（包括两种酸性蛋白质）。这些蛋白质按照卡尔施密特和维特曼的系统进行编号。
