大鼠肝多聚核糖体及其mRNA的分离和鉴定

Isolation and characterization of rat liver polyribosomes

利用超速离心法分离大鼠肝多聚核糖体,进一步用Oligo(dT)-Cellulose柱层析法从中直接分离出mRNA。紫外分光光度及蔗糖密度梯度分析均显示此多聚核糖体有较高的纯度。在兔网织红细胞体外翻译系统中,此多聚核糖体表现出较高的生物活性。

As the first step of selecting a spicific mRNA, we would have polyribosomes available. We used ultracentrifugation method to isolate polyribosomes from rat liver. The UV spectrum and A260/A280 ratio of this preparation showed the characteristics of polyribosomes, so did the sedimentation analysis,which was carried out through a sucrose gradient ( 20%-55% ) . In a cell-free system of rabbit re-ticulocyte lysate, the polyribosomes could stimulate radioactive incorpration of 〔35S〕 methionine into the proteins, about six times as greatly as the endogenous incorporation. Fluorography of the in vitro translation products showed that more proteins were synthesized when the polyribosomes existed. All the above confirmed that we had got pure, intact and active polyribosomes.