Hruby D E, Maki R A, Cummings D J
Biochim Biophys Acta. 1977 Jul 15;477(2):89-96. doi: 10.1016/0005-2787(77)90224-6.
Total cellular RNA was isolated from the ciliate protozoan Paramecium aurelia by pH 9.5 chloroform/octanol extraction. Passage of this RNA through an oligo(dT)-cellulose column in 0.5 M NaCl resulted in 2--3% binding, indicating the presence of polyadenylic acid sequences. These polyadenylic acid regions were estimated to be 250-500 nucleotides in length, based on their resistance to ribonuclease degradation. The oligo(dT)-cellulose bound RNA sedimented at 14--25 S in sodium dodecyl sulphate/sucrose gradients. The base composition of this RNA is similar to the base composition of the DNA. This RNA was also actively translated into protein by an in vitro protein synthesizing system isolated from wheat germ. Translation was optimal under conditions similar to those used for mammalian mRNA translation. In addition, translation of the P. aurelia oligo(dT)-cellulose bound RNA was inhibited 80% by the analog 7-methylguanosine-5'-phosphate, suggesting the presence of a 5'-capped terminus.
通过pH 9.5氯仿/辛醇萃取法从纤毛虫原生动物双小核草履虫中分离出总细胞RNA。将该RNA在0.5M NaCl中通过寡聚（dT）-纤维素柱，结果显示有2%-3%的结合，表明存在聚腺苷酸序列。基于它们对核糖核酸酶降解的抗性，这些聚腺苷酸区域估计长度为250-500个核苷酸。寡聚（dT）-纤维素结合的RNA在十二烷基硫酸钠/蔗糖梯度中以14-25S沉降。该RNA的碱基组成与DNA的碱基组成相似。这种RNA还能被从小麦胚芽中分离出的体外蛋白质合成系统有效地翻译成蛋白质。在与用于哺乳动物mRNA翻译相似的条件下，翻译效果最佳。此外，双小核草履虫寡聚（dT）-纤维素结合RNA的翻译被类似物7-甲基鸟苷-5'-磷酸抑制了80%，这表明存在5'-帽状末端。
