Oborotova T A, Berman A E, Mazurov V I
Biokhimiia. 1979 Sep;44(9):1715-20.
Free polyribosomes and polyribosomes bound to endoplasmic membranes were isolated from 10-day-old chick embryos by differential centrifugation. The tightly and loosely bound polyribosomal fractions were isolated from the membrane-bound polyribosomes using 0,5 M KCl. The synthesis of collagen and non-collagen proteins on the polyribosomes were studied in a homologous cell-free system. It was shown that the polyribosomes tightly bound to the membranes possess a lower protein-synthesizing activity as compared to free and loosely bound polyribosomes. The amount of bacterial collagenase-cleaved polypeptides in the protein product synthesized on the polyribosomes tightly and loosely bound to the memranes and on free polyribosomes is 31, 23 and 9%, respectively. The data obtained suggest that the loosely bound polyribosomes are actively involved in collagen synthesis and that this fraction is not a contamination of free polyribosomes in the preparations of totally bound polyribosomes. The role of tightly and loosely bound polyribosomes in the formation of the membrane polyribosomal complex is discussed.
通过差速离心从10日龄鸡胚中分离出游离多核糖体和附着在内质网膜上的多核糖体。使用0.5M KCl从膜结合多核糖体中分离出紧密结合和松散结合的多核糖体组分。在同源无细胞系统中研究了多核糖体上胶原蛋白和非胶原蛋白的合成。结果表明，与游离和松散结合的多核糖体相比，紧密结合在膜上的多核糖体具有较低的蛋白质合成活性。在紧密和松散结合在膜上的多核糖体以及游离多核糖体上合成的蛋白质产物中，细菌胶原酶切割的多肽量分别为31%、23%和9%。所得数据表明，松散结合的多核糖体积极参与胶原蛋白合成，并且该组分不是完全结合的多核糖体制剂中游离多核糖体的污染物。讨论了紧密和松散结合的多核糖体在膜多核糖体复合物形成中的作用。
