Jeffery W R
Biochim Biophys Acta. 1978 Nov 21;521(1):217-28. doi: 10.1016/0005-2787(78)90264-2.
Ribonucleoprotein fragments were isolated from Ehrlich ascites cell messenger ribonucleoprotein (mRNP), immobilized on oligo(dT)-cellulose, by successive RNAase and formamide treatments and their RNA and protein moieties were characterized. A 8--10 S formamide-eluted (F) RNP primarily contained the poly(A) segment as an RNA moiety, as evidenced by its characteristic electrophoretic mobility, resistance to RNAase digestion, affinity for nitrocellulose filters and poly(U), and base composition. In contrast, the RNAase-eluted (R) fraction was composed of a 2--3 S RNP carrying a much shorter polyribonucleotide fragment of heterogeneous base composition and properties unlike poly(A). Sodium dodecyl sulfate-polyacrylamide electrophoresis indicated that the protein moieties of the R fraction were composed primarily of 56 000, 67 000, and 71 000 molecular weight polypeptides whereas those of the F fraction contained the latter three polypeptides as well as a major species exhibiting a molecular weight of 81 000. The data demonstrate that RNA sequences other than poly(A) interact with protein in mRNP, that three major mRNP polypeptides are associated with both poly(A) and non-poly(A) RNA binding sites, and that one major polypeptide is specifically bound to the poly-(A) region of mRNP.
核糖核蛋白片段从艾氏腹水癌细胞信使核糖核蛋白（mRNP）中分离出来，通过连续的核糖核酸酶和甲酰胺处理固定在寡聚（dT）-纤维素上，并对其RNA和蛋白质部分进行了表征。一种8 - 10S甲酰胺洗脱（F）的核糖核蛋白主要含有作为RNA部分的聚（A）片段，这通过其特征性的电泳迁移率、对核糖核酸酶消化的抗性、对硝酸纤维素滤膜和聚（U）的亲和力以及碱基组成得以证明。相比之下，核糖核酸酶洗脱（R）部分由一种2 - 3S的核糖核蛋白组成，其携带的多聚核苷酸片段要短得多，碱基组成和性质与聚（A）不同。十二烷基硫酸钠 - 聚丙烯酰胺电泳表明，R部分的蛋白质部分主要由分子量为56000、67000和71000的多肽组成，而F部分的蛋白质部分除了含有后三种多肽外，还含有一种分子量为81000的主要成分。数据表明，除聚（A）以外的RNA序列在mRNP中与蛋白质相互作用，三种主要的mRNP多肽与聚（A）和非聚（A）RNA结合位点都有关联，并且一种主要多肽特异性地结合到mRNP的聚（A）区域。
